Here is a list of what was fixed since 11.5.7:

• 2022-03-08 f6401f696c [RELEASE] Release of TYPO3 11.5.8 (thanks to Benni Mack)
• 2022-03-07 ba45bfce26 [BUGFIX] Avoid trying to access array offset warning (thanks to Simon Ackermann)
• 2022-03-07 88a32d77c8 [TASK] Remove superfluous function call (thanks to Daniel)
• 2022-03-07 da7c94382b [BUGFIX] Do not cast pid to int in AddRecord (thanks to Oliver Bartsch)
• 2022-03-07 140a2eb639 [TASK] Move TS condition check to TS condition matcher (thanks to Helmut Hummel)
• 2022-03-07 70f3da0733 [BUGFIX] Fix HMENU / LanguageMenuProcessor for translated pages (thanks to Benni Mack)
• 2022-03-07 21d9c800bf [BUGFIX] Fix felogin GET/POST redirect mode (thanks to Torben Hansen)
• 2022-03-07 f1f6b54860 [BUGFIX] Avoid deprecation in PHP 8.1 passing null value to HtmlViewHelper (thanks to Chris Müller)
• 2022-03-05 8f1f8310ff [BUGFIX] Cast return value of method formMaxWidth to int (thanks to Nikita Hovratov)
• 2022-03-05 36c827fcee [BUGFIX] Fix typo in CategoryElement class constant (thanks to Nikita Hovratov)
• 2022-03-04 b51bf2846a [TASK] Provide forward-compatible CompositeExpression/ExpressionBuilder (thanks to Stefan Bürk)
• 2022-03-04 0ecaf94ad3 [TASK] Add request tests for DELETE,PATCH,PUT AND POST with data (thanks to Stefan Bürk)
• 2022-03-04 95f3c9c968 [BUGFIX] Set pid in AddController for new records (thanks to Susanne Moog)
• 2022-03-04 a35123f95f [BUGFIX] Undefined array key warning in static routes (thanks to Jochen Roth)
• 2022-03-04 237ad762ad [BUGFIX] Fix undefined array key warning in HMENU & TMENU (thanks to André Buchmann)
• 2022-03-04 3e0971218c [TASK] Add expressive API to ProcessingRule class (thanks to Helmut Hummel)
• 2022-03-04 dc3c914c94 [DOCS] Customization of the form editor (thanks to Björn Jacob)
• 2022-03-04 966a2f86d4 [TASK] Raise PHPStan to version 1.4.8 (thanks to Nikita Hovratov)
• 2022-03-04 99f85760d5 [BUGFIX] Fix undefined array key warning in HtmlParser (thanks to André Buchmann)
• 2022-03-04 d31ea25faf [BUGFIX] Fix typo in PHPDoc of LocalizationUtility::translate (thanks to Max Rösch)
• 2022-03-04 a96c1edeb7 [BUGFIX] Fix type error in TcaItemsProcessorFunctions (thanks to Georg Ringer)
• 2022-03-03 43101916b0 [BUGFIX] Fix PHP 8.0 warning with inline sychronize (thanks to Christian Kuhn)
• 2022-03-03 da8be96875 [BUGFIX] Fix undefined array key warning in GifBuilder (thanks to André Buchmann)
• 2022-03-02 f1ba2b93ea [BUGFIX] Prevent PHP warning for invalid page title in PageLinkHandler (thanks to Oliver Bartsch)
• 2022-03-01 4ed0254b46 [DOCS] Fix title and code example of changelog (thanks to Oliver Bartsch)
• 2022-03-01 390f4eb20c [BUGFIX] Use proper flags for htmlspecialchars() in "View Documentation" (thanks to Stefan Bürk)
• 2022-03-01 33e2f72a85 [TASK] Improve accesibility of workspace module (thanks to Georg Ringer)
• 2022-03-01 fc6d86ee2e [BUGFIX] Raise doctrine/lexer:"^1.2.3" (thanks to Stefan Bürk)
• 2022-03-01 e20b0dd866 [TASK] Make labels in FormEditor translatable (thanks to Oliver Bartsch)
• 2022-03-01 440d691933 [TASK] Allow extension scanner reporting for dirs outside typo3conf (thanks to Kevin Appelt)
• 2022-02-27 6e185794a5 [BUGFIX] phpstan: declare return type of forwardOnFieldChangeQueryParams (thanks to Andreas Fernandez)
• 2022-02-27 9fcb6f3f04 [BUGFIX] Raise doctrine/lexer:"^1.2.2" (thanks to Stefan Bürk)
• 2022-02-27 bed06ae7db [TASK] Fix the return type annotation of getIndpEnv (thanks to Oliver Klee)
• 2022-02-27 8e5e57413b [TASK] Allow private service container in tests (thanks to Benjamin Franzke)
• 2022-02-27 1862499439 [TASK] Minor bin/typo3 upgrade:run output improvement (thanks to Christian Kuhn)
• 2022-02-26 1eec029754 [DOCS] Documentation about form validators for editor (thanks to colin_44)
• 2022-02-26 4bf7eb1d8a [DOCS] Overview of form elements (thanks to colin.findeisen@tritum.de)
• 2022-02-26 f3d3f30291 [TASK] Allow in-memory caching of HTML sanitizer behavior (thanks to Oliver Hader)
• 2022-02-25 8542152d06 [DOCS] Overview validation messages used in EXT:form (thanks to Björn Jacob)
• 2022-02-25 24b406202d [BUGFIX] Add missing localization for error in DateRangeValidator (thanks to Elias Häußler)
• 2022-02-25 28cb0c2a91 [BUGFIX] Prevent YAML escaping from being displayed in form labels (thanks to Ralf Zimmermann)
• 2022-02-25 b31af24687 [DOCS] Add FAQ about duplicate form submission (thanks to Björn Jacob)
• 2022-02-25 57b345ada7 [BUGFIX] Recognize changes in FlexForm section containers (thanks to Elias Häußler)
• 2022-02-24 204049811b [BUGFIX] Discard 'new' workspace element when deleting live (thanks to Christian Kuhn)
• 2022-02-24 9c40b31c27 [BUGFIX] Add missing comma to array_merge() in WorkspaceService (thanks to checkmaldierethorik)
• 2022-02-24 3d8c8f034e [BUGFIX] Properly reset form renderable validators (thanks to Elias Häußler)
• 2022-02-24 61bf14ce6b [DOCS] Working with BCC recipients (thanks to Björn Jacob)
• 2022-02-24 ab08ae921c [DOCS] Fix sitemap rendering in EXT:form documentation (thanks to Elias Häußler)
• 2022-02-24 a1cbf79444 [BUGFIX] Restore contentObject condition in EXT:form (thanks to Georg Ringer)
• 2022-02-24 d914fb5536 [TASK] Raise typo3/cms-styleguide:"~11.5.4" (thanks to Stefan Bürk)
• 2022-02-23 3f35006966 [BUGFIX] Use per-language runtime cache for LanguageService (thanks to Jan Delius)
• 2022-02-22 1b78a2ef52 [TASK] CI: Only retry acceptance tests on failures (thanks to Stefan Bürk)
• 2022-02-22 0859afb4e1 [TASK] Set TYPO3 version to 11.5.8-dev (thanks to Oliver Hader)