Symfony 5.3.7 has just been released. Here is a list of the most
important changes:

bug #42769 [HttpClient] Don’t pass float to usleep() (@derrabus)
bug #42753 Cast ini_get to an integer to match expected type (@natewiebe13)
bug #42345 [Messenger] Remove indices in messenger table on MySQL to prevent deadlocks while removing messages when running multiple consumers (@jeroennoten)
bug #41378 [Messenger] Fix ErrorDetailsStamp denormalization (@wucdbm)
bug #42160 [Translation] Extract translatable content on twig set (@natewiebe13)
bug #42053 [Notifier] [Smsapi] fixed checking whether message is sent (@damlox)
bug #40744 allow null for framework.translator.default_path (@SimonHeimberg)
bug #39856 [DomCrawler] improve failure messages of the CrawlerSelectorTextContains constraint (@xabbuh)
bug #40545 [HttpFoundation] Fix isNotModified determination logic (@ol0lll)
bug #42368 [FrameworkBundle] Fall back to default configuration in debug:config and consistently resolve parameter values (@herndlm)
bug #41684 Fix Url Validator false positives (@sidz)
bug #42576 [Translation] Reverse fallback locales (@ro0NL)
bug #42721 Escape all special characters for parse_mode MARKDOWN_V2 (@thomas2411)
bug #42707 [Messenger] [AMQP] Do not leak any credentials when connection fails (@ruudk)
bug #42690 [Notifier] Firebase error handling (@mishaklomp)
bug #42628 [PropertyInfo] Support for the never return type (@derrabus)
bug #42685 Fix ProgressBar to correctly clear multi-line formats (@rtek)
bug #42649 [Translation] Fix message key handling for the Localise provider (@xepozz)
bug #42659 Ignoring X-Transport header while signing email with DKIM (@metaer)
bug #42585 [ExpressionLanguage] [Lexer] Remove PHP 8.0 polyfill (@nigelmann)
bug #42621 [Security] Don’t produce TypeErrors for non-string CSRF tokens (@derrabus)
bug #42596 [Security] Fix wrong cache directive when using the new PUBLIC_ACCESS attribute (@wouterj)
bug #42445 [Cache] fix wiring async cache recomputing in debug mode (@nicolas-grekas)
bug #42365 [Cache] Do not add namespace argument to NullAdapter in CachePoolPass (@olsavmic)
bug #42331 [HttpKernel] always close open stopwatch section after handling kernel.request events (@xabbuh)
bug #42381 [Console] Don’t pass null to preg_replace() (@derrabus)
bug #42347 Fix ServiceLocator indexing when service is decorated (@shyim)
bug #42380 [HttpFoundation] Don’t pass null to strpos() (@derrabus)
bug #42377 [HttpKernel] Remove preloading legacy event dispatcher (@OskarStark)
bug #42260 Fix return types for PHP 8.1 (@derrabus)
bug #42360 [DoctrineBridge] Typehint against doctrine/persistence interfaces (@malarzm)
bug #42341 [Validator] Update MIR card scheme (@ossinkine)
bug #42321 [PasswordHasher] Fix usage of PasswordHasherAdapter in PasswordHasherFactory (@peter17)

Want to upgrade to this new release? Because Symfony protects
backwards-compatibility very closely, this should be quite easy. Use
SymfonyInsight upgrade reports
to detect the code you will need to change in your project and
read our upgrade
documentation to learn more.

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