diff --git a/CHANGELOG-6.3.md b/CHANGELOG-6.3.md
index b98c8dfc740c5..9d3308e979be8 100644
--- a/CHANGELOG-6.3.md
+++ b/CHANGELOG-6.3.md
@@ -7,6 +7,40 @@ in 6.3 minor versions.
 To get the diff for a specific change, go to https://github.com/symfony/symfony/commit/XXX where XXX is the change hash
 To get the diff between two versions, go to https://github.com/symfony/symfony/compare/v6.3.0...v6.3.1
 
+* 6.3.4 (2023-08-26)
+
+ * bug #51475 [Serializer] Fix union of enum denormalization (mtarld)
+ * bug #51474 [Serializer] Fix wrong InvalidArgumentException thrown (mtarld)
+ * bug #51494 Fixed attachment base64 content string in MailerSendApiTransport (pavelwitassek)
+ * bug #51350 [Security] Prevent creating session in stateless firewalls (Seb33300)
+ * bug #51104 [Security] Fix loading user from UserBadge (guillaumesmo)
+ * bug #51473 [VarDumper] Fix managing collapse state in CliDumper (nicolas-grekas)
+ * bug #51369 [Serializer] Fix deserializing object collection properties (X-Coder264)
+ * bug #51399 [Serializer] Fix deserializing of nested snake_case attributes using CamelCaseToSnakeCaseNameConverter (Victor-Truhanovich)
+ * bug #51456 [Serializer] Fix serialized name with groups during denormalization (mtarld)
+ * bug #51445 [Security] FormLoginAuthenticator: fail for non-string password (dmaicher)
+ * bug #51424 [HttpFoundation] Fix base URI detection on IIS with UrlRewriteModule (derrabus)
+ * bug #51396 [HttpKernel] Fix missing Request in RequestStack for StreamedResponse (Ismail Turan)
+ * bug #51378 [Console] avoid multiple new line when message already ends with a new line in section output (joelwurtz)
+ * bug #51336 [Notifier] [Pushover] Fix invalid method call + improve exception message (ahmedghanem00)
+ * bug #51345 [AssetMapper] Fixing bug where a circular exception could be thrown while making error message (weaverryan)
+ * bug #48840 [Validator] Dump Valid constraints on debug command (macintoshplus)
+ * bug #51223 [Console] Fix linewraps in `OutputFormatter` (maxbeckers)
+ * bug #51307 [DependencyInjection] fix dump xml with array/object/enum default value (Jean-Beru)
+ * bug #51355 [Console] fix section output when multiples section with max height (joelwurtz)
+ * bug #51359 [Security] Fix error with lock_factory in login_throttling (BaptisteContreras)
+ * bug #51326 [FrameworkBundle] Fix xsd for handle-all-throwables (Jean-Beru)
+ * bug #51328 [Messenger] Always return bool from messenger amqp connection nack (Danielss89)
+ * bug #51295 [Mailer] update Brevo SMTP host (bastien-wink)
+ * bug #51301 [FrameworkBundle] add missing default-doctrine-dbal-provider cache pool attribute to XSD (xabbuh)
+ * bug #51296 [Process] Fix silencing `wait` when using a sigchild-enabled binary (nicolas-grekas)
+ * bug #51251 [DependencyInjection] Do not add `return` in `LazyClosure` when return type of closure is `void` (ruudk)
+ * bug #51219 [DependencyInjection][HttpKernel] Fix using `#[AutowireCallable]` with controller arguments (HypeMC)
+ * bug #51201 [Workflow] fix MermaidDumper when place contains special char (lyrixx)
+ * bug #49195 [Crawler] Fix regression where cdata nodes will return empty string (NanoSector)
+ * bug #51061 [DoctrineBridge] Bugfix - Allow to remove LazyLoaded listeners by object (VincentLanglet)
+ * bug #51190 [Clock] load function only if not loaded before (xabbuh)
+
 * 6.3.3 (2023-07-31)
 
  * bug #51178 [Finder] Revert "Fix children condition in ExcludeDirectoryFilterIterator" (derrabus)
diff --git a/src/Symfony/Component/HttpKernel/Kernel.php b/src/Symfony/Component/HttpKernel/Kernel.php
index df3e33444db21..af4000b822d4a 100644
--- a/src/Symfony/Component/HttpKernel/Kernel.php
+++ b/src/Symfony/Component/HttpKernel/Kernel.php
@@ -76,12 +76,12 @@ abstract class Kernel implements KernelInterface, RebootableInterface, Terminabl
      */
     private static array $freshCache = [];
 
-    public const VERSION = '6.3.4-DEV';
+    public const VERSION = '6.3.4';
     public const VERSION_ID = 60304;
     public const MAJOR_VERSION = 6;
     public const MINOR_VERSION = 3;
     public const RELEASE_VERSION = 4;
-    public const EXTRA_VERSION = 'DEV';
+    public const EXTRA_VERSION = '';
 
     public const END_OF_MAINTENANCE = '01/2024';
     public const END_OF_LIFE = '01/2024';