diff --git a/changelog/unreleased/PR#4026-update-io-netty-netty-to-v4-2-9-final-branch-9x.yml b/changelog/unreleased/PR#4026-update-io-netty-netty-to-v4-2-9-final-branch-9x.yml
new file mode 100644
index 000000000000..4128ce0be81b
--- /dev/null
+++ b/changelog/unreleased/PR#4026-update-io-netty-netty-to-v4-2-9-final-branch-9x.yml
@@ -0,0 +1,7 @@
+title: Update io.netty:netty* to v4.2.9.Final (branch_9x)
+type: dependency_update
+authors:
+- name: solrbot
+links:
+- name: PR#4026
+  url: https://github.com/apache/solr/pull/4026
diff --git a/solr/licenses/netty-buffer-4.2.6.Final.jar.sha1 b/solr/licenses/netty-buffer-4.2.6.Final.jar.sha1
deleted file mode 100644
index 81bdfa82c4ca..000000000000
--- a/solr/licenses/netty-buffer-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-4dfa898e145ea6910b9e99388f35e0ad483a6dfa
diff --git a/solr/licenses/netty-buffer-4.2.9.Final.jar.sha1 b/solr/licenses/netty-buffer-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..d9da3e5ee3b5
--- /dev/null
+++ b/solr/licenses/netty-buffer-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+d419abb1b035e1ab4dae22766c3ebf37343cc82b
diff --git a/solr/licenses/netty-codec-base-4.2.6.Final.jar.sha1 b/solr/licenses/netty-codec-base-4.2.6.Final.jar.sha1
deleted file mode 100644
index 24a7260d2302..000000000000
--- a/solr/licenses/netty-codec-base-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-fd6ff9613696f99857daeca37d4cfed22b1eb69e
diff --git a/solr/licenses/netty-codec-base-4.2.9.Final.jar.sha1 b/solr/licenses/netty-codec-base-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..70319f24487a
--- /dev/null
+++ b/solr/licenses/netty-codec-base-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+1ecb17e188008c62aef9d03491f2fde6b06414bb
diff --git a/solr/licenses/netty-codec-compression-4.2.6.Final.jar.sha1 b/solr/licenses/netty-codec-compression-4.2.6.Final.jar.sha1
deleted file mode 100644
index dcb00931224e..000000000000
--- a/solr/licenses/netty-codec-compression-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-fadf334ce949ae99b96b4b9d95d59c30a5dc2614
diff --git a/solr/licenses/netty-codec-compression-4.2.9.Final.jar.sha1 b/solr/licenses/netty-codec-compression-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..8606ac7ddbdb
--- /dev/null
+++ b/solr/licenses/netty-codec-compression-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+d3d3c3c16110278d1dbf8a423e20a839523724cd
diff --git a/solr/licenses/netty-codec-http-4.2.6.Final.jar.sha1 b/solr/licenses/netty-codec-http-4.2.6.Final.jar.sha1
deleted file mode 100644
index 4921588924d6..000000000000
--- a/solr/licenses/netty-codec-http-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-26da0fb9215bde2ecd551b941ccb974f65f59884
diff --git a/solr/licenses/netty-codec-http-4.2.9.Final.jar.sha1 b/solr/licenses/netty-codec-http-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..7ec12e1d6fa0
--- /dev/null
+++ b/solr/licenses/netty-codec-http-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+20077d54b08a1cf7d764b169946373dff2e9f9be
diff --git a/solr/licenses/netty-codec-http2-4.2.6.Final.jar.sha1 b/solr/licenses/netty-codec-http2-4.2.6.Final.jar.sha1
deleted file mode 100644
index 4af577ab69b9..000000000000
--- a/solr/licenses/netty-codec-http2-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-55b556602dd5ae7adf7a0ef4720195138018a623
diff --git a/solr/licenses/netty-codec-http2-4.2.9.Final.jar.sha1 b/solr/licenses/netty-codec-http2-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..175310457375
--- /dev/null
+++ b/solr/licenses/netty-codec-http2-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+d82683120b05d1c9c56a88e1daff07e4c0420537
diff --git a/solr/licenses/netty-codec-socks-4.2.6.Final.jar.sha1 b/solr/licenses/netty-codec-socks-4.2.6.Final.jar.sha1
deleted file mode 100644
index 49a4e6ac7efb..000000000000
--- a/solr/licenses/netty-codec-socks-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-6e9de561de0b5764cf05be667c90a4fe06aba40c
diff --git a/solr/licenses/netty-codec-socks-4.2.9.Final.jar.sha1 b/solr/licenses/netty-codec-socks-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..fd355237f5f3
--- /dev/null
+++ b/solr/licenses/netty-codec-socks-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+95aeac38838c04094f30de6cc973c76c3270cfd3
diff --git a/solr/licenses/netty-common-4.2.6.Final.jar.sha1 b/solr/licenses/netty-common-4.2.6.Final.jar.sha1
deleted file mode 100644
index 4c0489f04e91..000000000000
--- a/solr/licenses/netty-common-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-5746874869298a07b468dd50b5991f457e773620
diff --git a/solr/licenses/netty-common-4.2.9.Final.jar.sha1 b/solr/licenses/netty-common-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..6980b1d9ced4
--- /dev/null
+++ b/solr/licenses/netty-common-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+04429addd1a59cb52dde76102f61b3f696fd3b9c
diff --git a/solr/licenses/netty-handler-4.2.6.Final.jar.sha1 b/solr/licenses/netty-handler-4.2.6.Final.jar.sha1
deleted file mode 100644
index 1ee1a3f7141c..000000000000
--- a/solr/licenses/netty-handler-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-311ea62f27b26685b306dc24c4bbf765bc1950d9
diff --git a/solr/licenses/netty-handler-4.2.9.Final.jar.sha1 b/solr/licenses/netty-handler-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..74249828fedb
--- /dev/null
+++ b/solr/licenses/netty-handler-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+f79da6a81f4390ed067301235e29705a7f774c5b
diff --git a/solr/licenses/netty-handler-proxy-4.2.6.Final.jar.sha1 b/solr/licenses/netty-handler-proxy-4.2.6.Final.jar.sha1
deleted file mode 100644
index 011354b13a8f..000000000000
--- a/solr/licenses/netty-handler-proxy-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-1f0f9fb2f321cc697f13d802cf80c37889ce421a
diff --git a/solr/licenses/netty-handler-proxy-4.2.9.Final.jar.sha1 b/solr/licenses/netty-handler-proxy-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..92465ed55426
--- /dev/null
+++ b/solr/licenses/netty-handler-proxy-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+3be91239e18159d66b647c8025629e13986236e4
diff --git a/solr/licenses/netty-resolver-4.2.6.Final.jar.sha1 b/solr/licenses/netty-resolver-4.2.6.Final.jar.sha1
deleted file mode 100644
index 243ced8a8f14..000000000000
--- a/solr/licenses/netty-resolver-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-121223f223094539282b916c303ac52c7875b9aa
diff --git a/solr/licenses/netty-resolver-4.2.9.Final.jar.sha1 b/solr/licenses/netty-resolver-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..516ab9719c75
--- /dev/null
+++ b/solr/licenses/netty-resolver-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+faccff808e9166f1d689e054059b172cffc738ab
diff --git a/solr/licenses/netty-tcnative-boringssl-static-2.0.73.Final.jar.sha1 b/solr/licenses/netty-tcnative-boringssl-static-2.0.73.Final.jar.sha1
deleted file mode 100644
index 0bea976dc344..000000000000
--- a/solr/licenses/netty-tcnative-boringssl-static-2.0.73.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-de7380a74a7611e9937dd2106abfde5b405dbd15
diff --git a/solr/licenses/netty-tcnative-boringssl-static-2.0.74.Final.jar.sha1 b/solr/licenses/netty-tcnative-boringssl-static-2.0.74.Final.jar.sha1
new file mode 100644
index 000000000000..c19d8959abd3
--- /dev/null
+++ b/solr/licenses/netty-tcnative-boringssl-static-2.0.74.Final.jar.sha1
@@ -0,0 +1 @@
+536b68a3bdabab178c042402150309db00e8f54d
diff --git a/solr/licenses/netty-tcnative-classes-2.0.73.Final.jar.sha1 b/solr/licenses/netty-tcnative-classes-2.0.73.Final.jar.sha1
deleted file mode 100644
index 048e8b91eba6..000000000000
--- a/solr/licenses/netty-tcnative-classes-2.0.73.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-f50d875a46e4a7768f35dbc26fb796fd791b8b09
diff --git a/solr/licenses/netty-tcnative-classes-2.0.74.Final.jar.sha1 b/solr/licenses/netty-tcnative-classes-2.0.74.Final.jar.sha1
new file mode 100644
index 000000000000..6b8889366709
--- /dev/null
+++ b/solr/licenses/netty-tcnative-classes-2.0.74.Final.jar.sha1
@@ -0,0 +1 @@
+c3b2e6ac13230849355f7ecaaeb12668a22e9c0a
diff --git a/solr/licenses/netty-transport-4.2.6.Final.jar.sha1 b/solr/licenses/netty-transport-4.2.6.Final.jar.sha1
deleted file mode 100644
index 98d517fa9a0e..000000000000
--- a/solr/licenses/netty-transport-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-15af02f1735db36455f2af2fd11b64e9f4499008
diff --git a/solr/licenses/netty-transport-4.2.9.Final.jar.sha1 b/solr/licenses/netty-transport-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..449728da4d15
--- /dev/null
+++ b/solr/licenses/netty-transport-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+b864fc8ec3d72b6e22af88f5408b6ad7e41980ec
diff --git a/solr/licenses/netty-transport-classes-epoll-4.2.6.Final.jar.sha1 b/solr/licenses/netty-transport-classes-epoll-4.2.6.Final.jar.sha1
deleted file mode 100644
index 0ca17ecbfc24..000000000000
--- a/solr/licenses/netty-transport-classes-epoll-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-b61968c0cb9c474df7a0ddc7cd577fed677efbbb
diff --git a/solr/licenses/netty-transport-classes-epoll-4.2.9.Final.jar.sha1 b/solr/licenses/netty-transport-classes-epoll-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..a57c220b28a1
--- /dev/null
+++ b/solr/licenses/netty-transport-classes-epoll-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+334ba203f5b5ac6372286d27115605431e5a37d3
diff --git a/solr/licenses/netty-transport-native-epoll-4.2.6.Final-linux-x86_64.jar.sha1 b/solr/licenses/netty-transport-native-epoll-4.2.6.Final-linux-x86_64.jar.sha1
deleted file mode 100644
index 9321b9107165..000000000000
--- a/solr/licenses/netty-transport-native-epoll-4.2.6.Final-linux-x86_64.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-c4a2ba3782e65b34bbb54c3a6636b466955dc1c6
diff --git a/solr/licenses/netty-transport-native-epoll-4.2.9.Final-linux-x86_64.jar.sha1 b/solr/licenses/netty-transport-native-epoll-4.2.9.Final-linux-x86_64.jar.sha1
new file mode 100644
index 000000000000..dd8099f8ed55
--- /dev/null
+++ b/solr/licenses/netty-transport-native-epoll-4.2.9.Final-linux-x86_64.jar.sha1
@@ -0,0 +1 @@
+345e9bc0118e2d0bb498d0fa10947a3295d30496
diff --git a/solr/licenses/netty-transport-native-unix-common-4.2.6.Final.jar.sha1 b/solr/licenses/netty-transport-native-unix-common-4.2.6.Final.jar.sha1
deleted file mode 100644
index 3c96938f2b63..000000000000
--- a/solr/licenses/netty-transport-native-unix-common-4.2.6.Final.jar.sha1
+++ /dev/null
@@ -1 +0,0 @@
-cacd60c080051c74b9487074cf89d28ec892d71c
diff --git a/solr/licenses/netty-transport-native-unix-common-4.2.9.Final.jar.sha1 b/solr/licenses/netty-transport-native-unix-common-4.2.9.Final.jar.sha1
new file mode 100644
index 000000000000..14e9b5ea0f8f
--- /dev/null
+++ b/solr/licenses/netty-transport-native-unix-common-4.2.9.Final.jar.sha1
@@ -0,0 +1 @@
+0ff416b5aaac1fbfe625ee92deb08664e938aa00
diff --git a/versions.lock b/versions.lock
index b99b5dd0c59d..d9e3f884d1f5 100644
--- a/versions.lock
+++ b/versions.lock
@@ -114,23 +114,23 @@ io.grpc:grpc-util:1.65.1 (2 constraints: ec1876f9)
 io.grpc:grpc-xds:1.65.1 (1 constraints: 1f100ba6)
 io.jaegertracing:jaeger-core:1.8.1 (2 constraints: 6f124721)
 io.jaegertracing:jaeger-thrift:1.8.1 (1 constraints: 0c050936)
-io.netty:netty-bom:4.2.6.Final (1 constraints: 2607ed5a)
-io.netty:netty-buffer:4.2.6.Final (12 constraints: 93b4ecc9)
-io.netty:netty-codec-base:4.2.6.Final (7 constraints: 8d5f3e44)
-io.netty:netty-codec-compression:4.2.6.Final (2 constraints: 4a18b09e)
-io.netty:netty-codec-http:4.2.6.Final (4 constraints: 7e2ec1d0)
-io.netty:netty-codec-http2:4.2.6.Final (2 constraints: dd158907)
-io.netty:netty-codec-socks:4.2.6.Final (2 constraints: ac196ff4)
-io.netty:netty-common:4.2.6.Final (14 constraints: 9fcdf69f)
-io.netty:netty-handler:4.2.6.Final (5 constraints: db4410c9)
-io.netty:netty-handler-proxy:4.2.6.Final (2 constraints: dd158907)
-io.netty:netty-resolver:4.2.6.Final (3 constraints: ba2429ff)
-io.netty:netty-tcnative-boringssl-static:2.0.73.Final (2 constraints: cf1ad957)
-io.netty:netty-tcnative-classes:2.0.73.Final (2 constraints: d21e0195)
-io.netty:netty-transport:4.2.6.Final (11 constraints: 16a7be79)
-io.netty:netty-transport-classes-epoll:4.2.6.Final (2 constraints: 491d6c04)
-io.netty:netty-transport-native-epoll:4.2.6.Final (2 constraints: d61a4e5f)
-io.netty:netty-transport-native-unix-common:4.2.6.Final (5 constraints: a647dc44)
+io.netty:netty-bom:4.2.9.Final (1 constraints: 2907025b)
+io.netty:netty-buffer:4.2.9.Final (12 constraints: b7b427ef)
+io.netty:netty-codec-base:4.2.9.Final (7 constraints: a25fdc4e)
+io.netty:netty-codec-compression:4.2.9.Final (2 constraints: 5018529f)
+io.netty:netty-codec-http:4.2.9.Final (4 constraints: 8a2ef1d3)
+io.netty:netty-codec-http2:4.2.9.Final (2 constraints: e0159e07)
+io.netty:netty-codec-socks:4.2.9.Final (2 constraints: b2191af5)
+io.netty:netty-common:4.2.9.Final (14 constraints: c9cde8d1)
+io.netty:netty-handler:4.2.9.Final (5 constraints: e74489ce)
+io.netty:netty-handler-proxy:4.2.9.Final (2 constraints: e0159e07)
+io.netty:netty-resolver:4.2.9.Final (3 constraints: c324d000)
+io.netty:netty-tcnative-boringssl-static:2.0.74.Final (2 constraints: d01a0e58)
+io.netty:netty-tcnative-classes:2.0.74.Final (2 constraints: d41e4795)
+io.netty:netty-transport:4.2.9.Final (11 constraints: 37a75399)
+io.netty:netty-transport-classes-epoll:4.2.9.Final (2 constraints: 4f1d3205)
+io.netty:netty-transport-native-epoll:4.2.9.Final (2 constraints: d91af05f)
+io.netty:netty-transport-native-unix-common:4.2.9.Final (5 constraints: b247b148)
 io.opencensus:opencensus-api:0.31.1 (5 constraints: 924d4692)
 io.opencensus:opencensus-contrib-http-util:0.31.1 (3 constraints: 7232a9fc)
 io.opencensus:opencensus-proto:0.2.0 (1 constraints: e60fd595)
diff --git a/versions.props b/versions.props
index b95645350ce2..4cb17ef6aa10 100644
--- a/versions.props
+++ b/versions.props
@@ -27,7 +27,7 @@ dev.langchain4j:langchain4j-*=0.35.0
 io.dropwizard.metrics:*=4.2.26
 io.grpc:grpc-*=1.65.1
 io.jaegertracing:*=1.8.1
-io.netty:netty*=4.2.6.Final
+io.netty:netty*=4.2.9.Final
 io.netty:netty-tcnative*=2.0.73.Final
 io.opentelemetry:opentelemetry-bom=1.53.0
 io.opentracing:opentracing*=0.33.0