diff --git a/.golangci.yml b/.golangci.yml
index 104cf923ce..f94c70575a 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -152,6 +152,13 @@ linters:
       - common-false-positives
       - legacy
       - std-error-handling
+    rules:
+      # go-elasticsearch v9 keeps the legacy Config/NewClient API fully
+      # functional. Fleet Server still relies on that API while the option-based
+      # client configuration is migrated separately.
+      - linters:
+          - staticcheck
+        text: "SA1019: elasticsearch\\.(Config|NewClient) is deprecated"
       # Which file paths to exclude: they will be analyzed, but issues from them won't be reported.
       # "/" will be replaced by the current OS file path separator to properly work on Windows.
       # Default: []
diff --git a/NOTICE-fips.txt b/NOTICE-fips.txt
index e754c10ace..369fee56e6 100644
--- a/NOTICE-fips.txt
+++ b/NOTICE-fips.txt
@@ -1082,12 +1082,12 @@ Contents of probable licence file $GOMODCACHE/github.com/elastic/elastic-agent-s
 
 
 --------------------------------------------------------------------------------
-Dependency : github.com/elastic/go-elasticsearch/v8
-Version: v8.19.6
+Dependency : github.com/elastic/go-elasticsearch/v9
+Version: v9.5.0
 Licence type (autodetected): Apache-2.0
 --------------------------------------------------------------------------------
 
-Contents of probable licence file $GOMODCACHE/github.com/elastic/go-elasticsearch/v8@v8.19.6/LICENSE:
+Contents of probable licence file $GOMODCACHE/github.com/elastic/go-elasticsearch/v9@v9.5.0/LICENSE:
 
                                  Apache License
                            Version 2.0, January 2004
diff --git a/NOTICE.txt b/NOTICE.txt
index 40c75e78f6..333bc66765 100644
--- a/NOTICE.txt
+++ b/NOTICE.txt
@@ -1082,12 +1082,12 @@ Contents of probable licence file $GOMODCACHE/github.com/elastic/elastic-agent-s
 
 
 --------------------------------------------------------------------------------
-Dependency : github.com/elastic/go-elasticsearch/v8
-Version: v8.19.6
+Dependency : github.com/elastic/go-elasticsearch/v9
+Version: v9.5.0
 Licence type (autodetected): Apache-2.0
 --------------------------------------------------------------------------------
 
-Contents of probable licence file $GOMODCACHE/github.com/elastic/go-elasticsearch/v8@v8.19.6/LICENSE:
+Contents of probable licence file $GOMODCACHE/github.com/elastic/go-elasticsearch/v9@v9.5.0/LICENSE:
 
                                  Apache License
                            Version 2.0, January 2004
diff --git a/go.mod b/go.mod
index a2e3effe2d..6b9f2947f4 100644
--- a/go.mod
+++ b/go.mod
@@ -10,7 +10,7 @@ require (
 	github.com/elastic/elastic-agent-client/v7 v7.18.1
 	github.com/elastic/elastic-agent-libs v0.46.2
 	github.com/elastic/elastic-agent-system-metrics v0.14.4
-	github.com/elastic/go-elasticsearch/v8 v8.19.6
+	github.com/elastic/go-elasticsearch/v9 v9.5.0
 	github.com/elastic/go-ucfg v0.9.1
 	github.com/fxamacker/cbor/v2 v2.9.2
 	github.com/go-chi/chi/v5 v5.3.1
diff --git a/go.sum b/go.sum
index a4c8954a78..547ce97fc7 100644
--- a/go.sum
+++ b/go.sum
@@ -43,8 +43,8 @@ github.com/elastic/elastic-agent-system-metrics v0.14.4 h1:XGGepNVOxhtfJmanQsgqC
 github.com/elastic/elastic-agent-system-metrics v0.14.4/go.mod h1:NyNMrdqMfznb/Zy8EmIAHlJpX6HuRlNW+bBL9UN7WQY=
 github.com/elastic/elastic-transport-go/v8 v8.9.0 h1:KeT/2P54F0xS0S8Y3Pf+tFDg4HmBgReQMB+BMz8dDAs=
 github.com/elastic/elastic-transport-go/v8 v8.9.0/go.mod h1:ssMTvNS2hwf7CaiGsRRsx4gQHFZ/jS/DkLcISxekWzc=
-github.com/elastic/go-elasticsearch/v8 v8.19.6 h1:4qa7ecJkr5rLsoHKIVGbaqcFt2o57CnOHQJi9Pts/rk=
-github.com/elastic/go-elasticsearch/v8 v8.19.6/go.mod h1:jeWebApE1oFEW/hKZqx/IRYmP/aa2+WMJkOfk+AduSI=
+github.com/elastic/go-elasticsearch/v9 v9.5.0 h1:ye9pnajcrSE2Fra0Q++nJsi09p2dJTaN6YXKz7LL7WU=
+github.com/elastic/go-elasticsearch/v9 v9.5.0/go.mod h1:EbZnYlTlbhNqRt98YW+QSM2SEKplN5o8J+G6d9STOVo=
 github.com/elastic/go-structform v0.0.12 h1:HXpzlAKyej8T7LobqKDThUw7BMhwV6Db24VwxNtgxCs=
 github.com/elastic/go-structform v0.0.12/go.mod h1:CZWf9aIRYY5SuKSmOhtXScE5uQiLZNqAFnwKR4OrIM4=
 github.com/elastic/go-sysinfo v1.15.1 h1:zBmTnFEXxIQ3iwcQuk7MzaUotmKRp3OabbbWM8TdzIQ=
diff --git a/internal/pkg/api/handleFileDelivery.go b/internal/pkg/api/handleFileDelivery.go
index b49681cfd1..bdc63aab8f 100644
--- a/internal/pkg/api/handleFileDelivery.go
+++ b/internal/pkg/api/handleFileDelivery.go
@@ -22,7 +22,7 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/file"
 	"github.com/elastic/fleet-server/v7/internal/pkg/file/delivery"
 	"github.com/elastic/fleet-server/v7/internal/pkg/model"
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 var (
diff --git a/internal/pkg/api/handleUpload.go b/internal/pkg/api/handleUpload.go
index dbc533dd40..1c9ee825d6 100644
--- a/internal/pkg/api/handleUpload.go
+++ b/internal/pkg/api/handleUpload.go
@@ -27,7 +27,7 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/file/cbor"
 	"github.com/elastic/fleet-server/v7/internal/pkg/file/uploader"
 	"github.com/elastic/fleet-server/v7/internal/pkg/model"
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 const (
diff --git a/internal/pkg/api/handleUpload_test.go b/internal/pkg/api/handleUpload_test.go
index c7a11933fc..89378b5b4f 100644
--- a/internal/pkg/api/handleUpload_test.go
+++ b/internal/pkg/api/handleUpload_test.go
@@ -31,7 +31,7 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/file/uploader"
 	"github.com/elastic/fleet-server/v7/internal/pkg/model"
 	itesting "github.com/elastic/fleet-server/v7/internal/pkg/testing"
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
diff --git a/internal/pkg/apikey/apikey.go b/internal/pkg/apikey/apikey.go
index 0c4fee17e7..198b56c0f3 100644
--- a/internal/pkg/apikey/apikey.go
+++ b/internal/pkg/apikey/apikey.go
@@ -15,8 +15,8 @@ import (
 	"strings"
 	"unicode/utf8"
 
-	"github.com/elastic/go-elasticsearch/v8"
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 )
 
 const (
diff --git a/internal/pkg/apikey/apikey_integration_test.go b/internal/pkg/apikey/apikey_integration_test.go
index 42f24a4545..5e1a1b6e4a 100644
--- a/internal/pkg/apikey/apikey_integration_test.go
+++ b/internal/pkg/apikey/apikey_integration_test.go
@@ -12,7 +12,7 @@ import (
 
 	testlog "github.com/elastic/fleet-server/v7/internal/pkg/testing/log"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"github.com/gofrs/uuid/v5"
 	"github.com/google/go-cmp/cmp"
 )
diff --git a/internal/pkg/apikey/auth.go b/internal/pkg/apikey/auth.go
index af05e0ecd0..37c23c5766 100644
--- a/internal/pkg/apikey/auth.go
+++ b/internal/pkg/apikey/auth.go
@@ -11,8 +11,8 @@ import (
 	"fmt"
 	"net/http"
 
-	"github.com/elastic/go-elasticsearch/v8"
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 
 	"github.com/elastic/fleet-server/v7/internal/pkg/es"
 )
diff --git a/internal/pkg/apikey/auth_test.go b/internal/pkg/apikey/auth_test.go
index 797db557d5..44ebb472e5 100644
--- a/internal/pkg/apikey/auth_test.go
+++ b/internal/pkg/apikey/auth_test.go
@@ -12,7 +12,7 @@ import (
 	"testing"
 
 	"github.com/elastic/fleet-server/v7/internal/pkg/testing/esutil"
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"github.com/stretchr/testify/assert"
 )
 
diff --git a/internal/pkg/apikey/create.go b/internal/pkg/apikey/create.go
index dc5d333f5f..0cc9f825c9 100644
--- a/internal/pkg/apikey/create.go
+++ b/internal/pkg/apikey/create.go
@@ -10,8 +10,8 @@ import (
 	"encoding/json"
 	"fmt"
 
-	"github.com/elastic/go-elasticsearch/v8"
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 
 	"github.com/elastic/fleet-server/v7/internal/pkg/es"
 )
diff --git a/internal/pkg/apikey/invalidate.go b/internal/pkg/apikey/invalidate.go
index cbd651ad97..0479ab6832 100644
--- a/internal/pkg/apikey/invalidate.go
+++ b/internal/pkg/apikey/invalidate.go
@@ -10,8 +10,8 @@ import (
 	"encoding/json"
 	"fmt"
 
-	"github.com/elastic/go-elasticsearch/v8"
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 
 	"github.com/elastic/fleet-server/v7/internal/pkg/es"
 )
diff --git a/internal/pkg/bulk/engine.go b/internal/pkg/bulk/engine.go
index d5723255d6..8e8cd3a0c6 100644
--- a/internal/pkg/bulk/engine.go
+++ b/internal/pkg/bulk/engine.go
@@ -29,8 +29,8 @@ import (
 	"go.elastic.co/apm/v2"
 	"golang.org/x/sync/semaphore"
 
-	"github.com/elastic/go-elasticsearch/v8"
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 )
 
 type APIKey = apikey.APIKey
diff --git a/internal/pkg/bulk/helpers.go b/internal/pkg/bulk/helpers.go
index a5dda37ec4..2b9f5c68ac 100644
--- a/internal/pkg/bulk/helpers.go
+++ b/internal/pkg/bulk/helpers.go
@@ -10,7 +10,7 @@ import (
 	"io"
 
 	"github.com/elastic/fleet-server/v7/internal/pkg/es"
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 	"github.com/rs/zerolog"
 )
 
diff --git a/internal/pkg/bulk/opApiKey.go b/internal/pkg/bulk/opApiKey.go
index f831d5d81b..723e0befba 100644
--- a/internal/pkg/bulk/opApiKey.go
+++ b/internal/pkg/bulk/opApiKey.go
@@ -12,7 +12,7 @@ import (
 	"math"
 
 	"github.com/elastic/fleet-server/v7/internal/pkg/apikey"
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 	"github.com/rs/zerolog"
 	"go.elastic.co/apm/v2"
 )
diff --git a/internal/pkg/bulk/opBulk.go b/internal/pkg/bulk/opBulk.go
index 437b743a15..e332d532dd 100644
--- a/internal/pkg/bulk/opBulk.go
+++ b/internal/pkg/bulk/opBulk.go
@@ -11,7 +11,7 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 	"github.com/mailru/easyjson"
 	"github.com/rs/zerolog"
 	"go.elastic.co/apm/v2"
diff --git a/internal/pkg/bulk/opRead.go b/internal/pkg/bulk/opRead.go
index d7a17bd4c3..7b1b00c1f9 100644
--- a/internal/pkg/bulk/opRead.go
+++ b/internal/pkg/bulk/opRead.go
@@ -10,7 +10,7 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 	"github.com/mailru/easyjson"
 	"github.com/rs/zerolog"
 	"go.elastic.co/apm/v2"
diff --git a/internal/pkg/bulk/opSearch.go b/internal/pkg/bulk/opSearch.go
index 6ed83b6576..5e67061abf 100644
--- a/internal/pkg/bulk/opSearch.go
+++ b/internal/pkg/bulk/opSearch.go
@@ -13,7 +13,7 @@ import (
 
 	"github.com/elastic/fleet-server/v7/internal/pkg/es"
 	"github.com/elastic/fleet-server/v7/internal/pkg/sqn"
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 	"github.com/mailru/easyjson"
 	"github.com/rs/zerolog"
 	"go.elastic.co/apm/v2"
diff --git a/internal/pkg/bulk/secret.go b/internal/pkg/bulk/secret.go
index 1110912263..8a00f356ed 100644
--- a/internal/pkg/bulk/secret.go
+++ b/internal/pkg/bulk/secret.go
@@ -13,7 +13,7 @@ import (
 	"io"
 	"net/http"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"go.elastic.co/apm/v2"
 )
 
diff --git a/internal/pkg/bulk/secret_limit_test.go b/internal/pkg/bulk/secret_limit_test.go
index 24a62d7dae..7d20bf0a74 100644
--- a/internal/pkg/bulk/secret_limit_test.go
+++ b/internal/pkg/bulk/secret_limit_test.go
@@ -15,7 +15,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"github.com/stretchr/testify/require"
 )
 
diff --git a/internal/pkg/bulk/secret_test.go b/internal/pkg/bulk/secret_test.go
index ec20035984..b12a6a73f7 100644
--- a/internal/pkg/bulk/secret_test.go
+++ b/internal/pkg/bulk/secret_test.go
@@ -11,7 +11,7 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
diff --git a/internal/pkg/bulk/setup_test.go b/internal/pkg/bulk/setup_test.go
index 0af0eaa6d1..feca15cb5b 100644
--- a/internal/pkg/bulk/setup_test.go
+++ b/internal/pkg/bulk/setup_test.go
@@ -15,7 +15,7 @@ import (
 	"time"
 
 	"github.com/Pallinder/go-randomdata"
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"github.com/elastic/go-ucfg/yaml"
 	"github.com/rs/xid"
 
diff --git a/internal/pkg/checkin/bulk.go b/internal/pkg/checkin/bulk.go
index 3be9d94188..32810a86c9 100644
--- a/internal/pkg/checkin/bulk.go
+++ b/internal/pkg/checkin/bulk.go
@@ -20,8 +20,8 @@ import (
 
 	"github.com/rs/zerolog"
 
-	estypes "github.com/elastic/go-elasticsearch/v8/typedapi/types"
-	"github.com/elastic/go-elasticsearch/v8/typedapi/types/enums/scriptlanguage"
+	estypes "github.com/elastic/go-elasticsearch/v9/typedapi/types"
+	"github.com/elastic/go-elasticsearch/v9/typedapi/types/enums/scriptlanguage"
 )
 
 const defaultFlushInterval = 10 * time.Second
diff --git a/internal/pkg/config/output.go b/internal/pkg/config/output.go
index 277f41a477..27681c0196 100644
--- a/internal/pkg/config/output.go
+++ b/internal/pkg/config/output.go
@@ -22,7 +22,7 @@ import (
 	"github.com/elastic/elastic-agent-libs/transport/tlscommon"
 	"github.com/elastic/fleet-server/v7/internal/pkg/logger/zap"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"github.com/rs/zerolog"
 )
 
@@ -261,13 +261,13 @@ func (c *Elasticsearch) DiagRequests(ctx context.Context) []byte {
 		hostURL, err := makeURL(c.Protocol, "", host, 9200)
 		if err != nil {
 			zerolog.Ctx(ctx).Warn().Err(err).Str("host", host).Msg("Unable to transform host to url.URL")
-			res.WriteString(fmt.Sprintf("Unable to transform host %q to url.URL: %v\n", host, err))
+			fmt.Fprintf(&res, "Unable to transform host %q to url.URL: %v\n", host, err)
 			continue
 		}
 		req, err := http.NewRequestWithContext(ctx, http.MethodGet, hostURL, nil)
 		if err != nil {
 			zerolog.Ctx(ctx).Warn().Err(err).Str("host", host).Msg("Unable to create request to host")
-			res.WriteString(fmt.Sprintf("Unable to create request to host %q: %v\n", host, err))
+			fmt.Fprintf(&res, "Unable to create request to host %q: %v\n", host, err)
 			continue
 		}
 		req.Header = headers.Clone()
diff --git a/internal/pkg/config/output_test.go b/internal/pkg/config/output_test.go
index 566340fbbd..c41690fc1c 100644
--- a/internal/pkg/config/output_test.go
+++ b/internal/pkg/config/output_test.go
@@ -25,7 +25,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 
 	"github.com/elastic/elastic-agent-libs/transport/tlscommon"
 )
diff --git a/internal/pkg/dl/migration.go b/internal/pkg/dl/migration.go
index 5f39b2d6c2..13fedfd369 100644
--- a/internal/pkg/dl/migration.go
+++ b/internal/pkg/dl/migration.go
@@ -12,7 +12,7 @@ import (
 	"net/http"
 	"time"
 
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 	"github.com/rs/zerolog"
 
 	"github.com/elastic/fleet-server/v7/internal/pkg/bulk"
diff --git a/internal/pkg/es/client.go b/internal/pkg/es/client.go
index 420721ad4b..0dff6fd78f 100644
--- a/internal/pkg/es/client.go
+++ b/internal/pkg/es/client.go
@@ -22,7 +22,7 @@ import (
 	"github.com/rs/zerolog"
 
 	backoff "github.com/cenkalti/backoff/v7"
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 const (
diff --git a/internal/pkg/es/client_test.go b/internal/pkg/es/client_test.go
index c677a5dec4..a2cc88eb4d 100644
--- a/internal/pkg/es/client_test.go
+++ b/internal/pkg/es/client_test.go
@@ -24,7 +24,7 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/testing/certs"
 	"github.com/stretchr/testify/require"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 var enabled bool = true
diff --git a/internal/pkg/es/delete.go b/internal/pkg/es/delete.go
index 54014c6e4f..4f1cb8a2ce 100644
--- a/internal/pkg/es/delete.go
+++ b/internal/pkg/es/delete.go
@@ -8,7 +8,7 @@ import (
 	"context"
 	"encoding/json"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 func DeleteIndices(ctx context.Context, es *elasticsearch.Client, indices []string) error {
diff --git a/internal/pkg/es/info.go b/internal/pkg/es/info.go
index 99de8c1e29..a0aa924088 100644
--- a/internal/pkg/es/info.go
+++ b/internal/pkg/es/info.go
@@ -9,7 +9,7 @@ import (
 	"encoding/json"
 	"strings"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 type versionInfo struct {
diff --git a/internal/pkg/file/delivery/delivery.go b/internal/pkg/file/delivery/delivery.go
index 715bbfd911..ffbbc96de3 100644
--- a/internal/pkg/file/delivery/delivery.go
+++ b/internal/pkg/file/delivery/delivery.go
@@ -15,7 +15,7 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/bulk"
 	"github.com/elastic/fleet-server/v7/internal/pkg/file"
 	"github.com/elastic/fleet-server/v7/internal/pkg/file/cbor"
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"github.com/rs/zerolog"
 	"go.elastic.co/apm/v2"
 )
diff --git a/internal/pkg/file/delivery/delivery_test.go b/internal/pkg/file/delivery/delivery_test.go
index 4bbbb0bdf8..c6a47b4be6 100644
--- a/internal/pkg/file/delivery/delivery_test.go
+++ b/internal/pkg/file/delivery/delivery_test.go
@@ -20,7 +20,7 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/es"
 	"github.com/elastic/fleet-server/v7/internal/pkg/file"
 	itesting "github.com/elastic/fleet-server/v7/internal/pkg/testing"
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"github.com/rs/zerolog"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
diff --git a/internal/pkg/file/delivery/es.go b/internal/pkg/file/delivery/es.go
index 78bc66c16a..1b96ae903c 100644
--- a/internal/pkg/file/delivery/es.go
+++ b/internal/pkg/file/delivery/es.go
@@ -14,8 +14,8 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/dsl"
 	"github.com/elastic/fleet-server/v7/internal/pkg/es"
 	"github.com/elastic/fleet-server/v7/internal/pkg/file"
-	"github.com/elastic/go-elasticsearch/v8"
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 	"go.elastic.co/apm/v2"
 )
 
diff --git a/internal/pkg/file/uploader/es.go b/internal/pkg/file/uploader/es.go
index 5c85340c9f..45407e0f23 100644
--- a/internal/pkg/file/uploader/es.go
+++ b/internal/pkg/file/uploader/es.go
@@ -16,8 +16,8 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/es"
 	"github.com/elastic/fleet-server/v7/internal/pkg/file"
 	"github.com/elastic/fleet-server/v7/internal/pkg/file/cbor"
-	"github.com/elastic/go-elasticsearch/v8"
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 	"github.com/rs/zerolog"
 	"go.elastic.co/apm/v2"
 )
diff --git a/internal/pkg/file/uploader/upload.go b/internal/pkg/file/uploader/upload.go
index 6732a184d0..8c2880d0b8 100644
--- a/internal/pkg/file/uploader/upload.go
+++ b/internal/pkg/file/uploader/upload.go
@@ -15,7 +15,7 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/bulk"
 	"github.com/elastic/fleet-server/v7/internal/pkg/cache"
 	"github.com/elastic/fleet-server/v7/internal/pkg/file"
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"github.com/gofrs/uuid/v5"
 	"go.elastic.co/apm/v2"
 )
diff --git a/internal/pkg/gcheckpt/checkpoint.go b/internal/pkg/gcheckpt/checkpoint.go
index 6f0fc1164b..fe57447f1a 100644
--- a/internal/pkg/gcheckpt/checkpoint.go
+++ b/internal/pkg/gcheckpt/checkpoint.go
@@ -18,8 +18,8 @@ import (
 	esh "github.com/elastic/fleet-server/v7/internal/pkg/es"
 	"github.com/elastic/fleet-server/v7/internal/pkg/sqn"
 
-	"github.com/elastic/go-elasticsearch/v8"
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 )
 
 var ErrGlobalCheckpoint = errors.New("global checkpoint error")
diff --git a/internal/pkg/monitor/monitor.go b/internal/pkg/monitor/monitor.go
index e37e7f5e13..342eda4d2d 100644
--- a/internal/pkg/monitor/monitor.go
+++ b/internal/pkg/monitor/monitor.go
@@ -24,7 +24,7 @@ import (
 	"github.com/rs/zerolog"
 	"go.elastic.co/apm/v2"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 const (
@@ -101,7 +101,7 @@ type simpleMonitorT struct {
 }
 
 // Option is a functional configuration option.
-type Option func(SimpleMonitor)
+type Option func(*simpleMonitorT)
 
 // NewSimple creates new SimpleMonitor.
 func NewSimple(index string, esCli, monCli *elasticsearch.Client, opts ...Option) (SimpleMonitor, error) {
@@ -139,43 +139,43 @@ func NewSimple(index string, esCli, monCli *elasticsearch.Client, opts ...Option
 
 // WithFetchSize sets the fetch size of the monitor.
 func WithFetchSize(fetchSize int) Option {
-	return func(m SimpleMonitor) {
+	return func(m *simpleMonitorT) {
 		if fetchSize > 0 {
-			m.(*simpleMonitorT).fetchSize = fetchSize
+			m.fetchSize = fetchSize
 		}
 	}
 }
 
 // WithPollTimeout sets the global checkpoint polling timeout
 func WithPollTimeout(to time.Duration) Option {
-	return func(m SimpleMonitor) {
-		m.(*simpleMonitorT).pollTimeout = to
+	return func(m *simpleMonitorT) {
+		m.pollTimeout = to
 	}
 }
 
 // WithExpiration adds the expiration field to the monitor query.
 func WithExpiration(withExpiration bool) Option {
-	return func(m SimpleMonitor) {
-		m.(*simpleMonitorT).withExpiration = withExpiration
+	return func(m *simpleMonitorT) {
+		m.withExpiration = withExpiration
 	}
 }
 
 // WithReadyChan allows to pass the channel that will signal when monitor is ready.
 func WithReadyChan(readyCh chan error) Option {
-	return func(m SimpleMonitor) {
-		m.(*simpleMonitorT).readyCh = readyCh
+	return func(m *simpleMonitorT) {
+		m.readyCh = readyCh
 	}
 }
 
 func WithAPMTracer(tracer *apm.Tracer) Option {
-	return func(m SimpleMonitor) {
-		m.(*simpleMonitorT).tracer = tracer
+	return func(m *simpleMonitorT) {
+		m.tracer = tracer
 	}
 }
 
 func WithDebounceTime(dur time.Duration) Option {
-	return func(m SimpleMonitor) {
-		m.(*simpleMonitorT).debounceTime = dur
+	return func(m *simpleMonitorT) {
+		m.debounceTime = dur
 	}
 }
 
@@ -418,8 +418,8 @@ func (m *simpleMonitorT) search(ctx context.Context, tmpl *dsl.Tmpl, params map[
 
 	res, err := m.esCli.FleetSearch(
 		m.index,
+		bytes.NewBuffer(query),
 		m.esCli.FleetSearch.WithContext(ctx),
-		m.esCli.FleetSearch.WithBody(bytes.NewBuffer(query)),
 		m.esCli.FleetSearch.WithWaitForCheckpoints(seqNos.String()),
 	)
 	if err != nil {
diff --git a/internal/pkg/monitor/subscription_monitor.go b/internal/pkg/monitor/subscription_monitor.go
index eda62894f4..7535b6a932 100644
--- a/internal/pkg/monitor/subscription_monitor.go
+++ b/internal/pkg/monitor/subscription_monitor.go
@@ -14,7 +14,7 @@ import (
 	"github.com/elastic/fleet-server/v7/internal/pkg/sqn"
 	"github.com/rs/zerolog"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"golang.org/x/sync/errgroup"
 )
 
diff --git a/internal/pkg/server/fleet_integration_test.go b/internal/pkg/server/fleet_integration_test.go
index b34d9b1587..012a8d9dc6 100644
--- a/internal/pkg/server/fleet_integration_test.go
+++ b/internal/pkg/server/fleet_integration_test.go
@@ -33,7 +33,7 @@ import (
 	"golang.org/x/sync/errgroup"
 
 	"github.com/elastic/elastic-agent-client/v7/pkg/client"
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 
 	"github.com/elastic/fleet-server/v7/internal/pkg/api"
 	"github.com/elastic/fleet-server/v7/internal/pkg/apikey"
@@ -436,9 +436,8 @@ func TestServerUnauthorized(t *testing.T) {
 		srv.buildURL(agentID, "acks"),
 	}
 
-	allurls := []string{
-		srv.buildURL("", "enroll"),
-	}
+	allurls := make([]string, 0, 1+len(agenturls))
+	allurls = append(allurls, srv.buildURL("", "enroll"))
 	allurls = append(allurls, agenturls...)
 
 	// Expecting no authorization header error
diff --git a/internal/pkg/server/fleet_secrets_integration_test.go b/internal/pkg/server/fleet_secrets_integration_test.go
index 96c71a512e..928d095d7c 100644
--- a/internal/pkg/server/fleet_secrets_integration_test.go
+++ b/internal/pkg/server/fleet_secrets_integration_test.go
@@ -22,7 +22,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 
 	"github.com/elastic/fleet-server/v7/internal/pkg/api"
 	"github.com/elastic/fleet-server/v7/internal/pkg/apikey"
diff --git a/internal/pkg/server/otel_policy_secrets_integration_test.go b/internal/pkg/server/otel_policy_secrets_integration_test.go
index 95ca09324b..3a5659dbf7 100644
--- a/internal/pkg/server/otel_policy_secrets_integration_test.go
+++ b/internal/pkg/server/otel_policy_secrets_integration_test.go
@@ -20,7 +20,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 
 	"github.com/elastic/fleet-server/v7/internal/pkg/api"
 	"github.com/elastic/fleet-server/v7/internal/pkg/apikey"
diff --git a/internal/pkg/testing/bulk.go b/internal/pkg/testing/bulk.go
index f890b7b16b..8a5b6bb778 100644
--- a/internal/pkg/testing/bulk.go
+++ b/internal/pkg/testing/bulk.go
@@ -7,7 +7,7 @@ package testing
 import (
 	"context"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"github.com/rs/zerolog"
 	"github.com/stretchr/testify/mock"
 	"go.elastic.co/apm/v2"
diff --git a/internal/pkg/testing/esutil/bootstrap.go b/internal/pkg/testing/esutil/bootstrap.go
index c5bf60f001..f2e446869c 100644
--- a/internal/pkg/testing/esutil/bootstrap.go
+++ b/internal/pkg/testing/esutil/bootstrap.go
@@ -7,7 +7,7 @@ package esutil
 import (
 	"context"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 // EnsureIndex sets up the index if it doesn't exist. It's utilized for integration tests at the moment.
diff --git a/internal/pkg/testing/esutil/client.go b/internal/pkg/testing/esutil/client.go
index 5fbbdc33ae..7e636fbc4c 100644
--- a/internal/pkg/testing/esutil/client.go
+++ b/internal/pkg/testing/esutil/client.go
@@ -10,7 +10,7 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"github.com/stretchr/testify/require"
 )
 
diff --git a/internal/pkg/testing/esutil/datastream.go b/internal/pkg/testing/esutil/datastream.go
index 7fb1fb61fa..442f60cc68 100644
--- a/internal/pkg/testing/esutil/datastream.go
+++ b/internal/pkg/testing/esutil/datastream.go
@@ -12,7 +12,7 @@ import (
 
 	"github.com/rs/zerolog"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 func CreateDatastream(ctx context.Context, cli *elasticsearch.Client, name string) error {
diff --git a/internal/pkg/testing/esutil/esutil.go b/internal/pkg/testing/esutil/esutil.go
index e4a5949846..77f76be0f3 100644
--- a/internal/pkg/testing/esutil/esutil.go
+++ b/internal/pkg/testing/esutil/esutil.go
@@ -14,7 +14,7 @@ import (
 
 	"github.com/rs/zerolog"
 
-	"github.com/elastic/go-elasticsearch/v8/esapi"
+	"github.com/elastic/go-elasticsearch/v9/esapi"
 )
 
 const (
diff --git a/internal/pkg/testing/esutil/ilm.go b/internal/pkg/testing/esutil/ilm.go
index 817b0d2866..6ffad67b0a 100644
--- a/internal/pkg/testing/esutil/ilm.go
+++ b/internal/pkg/testing/esutil/ilm.go
@@ -14,7 +14,7 @@ import (
 
 	"github.com/rs/zerolog"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 // Can be cleaner but it's temporary bootstrap until it's moved to the elasticseach system index plugin
@@ -150,8 +150,9 @@ func createILMPolicy(ctx context.Context, cli *elasticsearch.Client, name string
 	// in that case let's just create the ILM policy
 	zerolog.Ctx(ctx).Debug().Str("policy", policy).Str("body", body).Msg("Creating ILM policy")
 
-	res, err := cli.ILM.PutLifecycle(policy,
-		cli.ILM.PutLifecycle.WithBody(strings.NewReader(body)),
+	res, err := cli.ILM.PutLifecycle(
+		strings.NewReader(body),
+		policy,
 		cli.ILM.PutLifecycle.WithContext(ctx),
 	)
 	if err != nil {
diff --git a/internal/pkg/testing/esutil/index.go b/internal/pkg/testing/esutil/index.go
index 8164c603e5..777d454ec1 100644
--- a/internal/pkg/testing/esutil/index.go
+++ b/internal/pkg/testing/esutil/index.go
@@ -12,7 +12,7 @@ import (
 
 	"github.com/rs/zerolog"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 func CreateIndex(ctx context.Context, cli *elasticsearch.Client, name string) error {
diff --git a/internal/pkg/testing/esutil/template.go b/internal/pkg/testing/esutil/template.go
index 93db2585f0..8f2221d198 100644
--- a/internal/pkg/testing/esutil/template.go
+++ b/internal/pkg/testing/esutil/template.go
@@ -14,7 +14,7 @@ import (
 
 	"github.com/rs/zerolog"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 const (
diff --git a/internal/pkg/testing/setup.go b/internal/pkg/testing/setup.go
index f011691484..b2113e2725 100644
--- a/internal/pkg/testing/setup.go
+++ b/internal/pkg/testing/setup.go
@@ -13,7 +13,7 @@ import (
 	"errors"
 	"testing"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 	"github.com/elastic/go-ucfg/yaml"
 	"github.com/rs/xid"
 
@@ -109,9 +109,9 @@ func CleanIndex(ctx context.Context, t *testing.T, bulker bulk.Bulk, index strin
 
 	cli := bulker.Client()
 
-	res, err := cli.API.DeleteByQuery([]string{index}, bytes.NewReader(query),
-		cli.API.DeleteByQuery.WithContext(ctx),
-		cli.API.DeleteByQuery.WithRefresh(true),
+	res, err := cli.DeleteByQuery([]string{index}, bytes.NewReader(query),
+		cli.DeleteByQuery.WithContext(ctx),
+		cli.DeleteByQuery.WithRefresh(true),
 	)
 	if err != nil {
 		t.Fatalf("could not clean index %s, DeleteByQuery failed: %v",
diff --git a/internal/pkg/ver/check.go b/internal/pkg/ver/check.go
index ec4eb263b8..c2fc4d9bd9 100644
--- a/internal/pkg/ver/check.go
+++ b/internal/pkg/ver/check.go
@@ -19,7 +19,7 @@ import (
 
 	"github.com/hashicorp/go-version"
 
-	"github.com/elastic/go-elasticsearch/v8"
+	"github.com/elastic/go-elasticsearch/v9"
 )
 
 // Variables to define errors when comparing versions.