Here is a list of what was fixed since 12.4.19:

• 2024-09-10 6d1d7bbd549 [RELEASE] Release of TYPO3 12.4.20 (thanks to Benni Mack)
• 2024-09-10 47b973215a3 [TASK] Drop @internal for sudo-mode AccessLifetime (thanks to Oliver Hader)
• 2024-09-09 ea440c6970a [TASK] Raise "phpstan/phpstan":"^1.12.3" (thanks to Stefan Bürk)
• 2024-09-09 40614fd98ab [BUGFIX] Allow non-english languages as xlf default language (thanks to Hannes Lau)
• 2024-09-09 3b367e8a494 [BUGFIX] Create same configuration in web and cli install process (thanks to Helmut Hummel)
• 2024-09-09 0c3ee279345 [BUGFIX] Allow "group" filter without "parameters" (thanks to Mathias Brodala)
• 2024-09-07 1abcc688594 [DOCS] Remove all highlight directives from dashboard docs (thanks to Lina Wolf)
• 2024-09-06 208b3445ef7 [BUGFIX] Mitigate exceptions in LogDataTrait::formatLogDetailsStatic (thanks to Thomas Hohn)
• 2024-09-05 fd712a3bdd1 [BUGFIX] Prevent PHP warning with missing items for checkboxToggle (thanks to Xavier Perseguers)
• 2024-09-05 c917d3d60a7 [BUGFIX] Wrong index in BackendLayoutView::getColPosListItemsParsed (thanks to Thomas Hohn)
• 2024-09-04 9b167768bb0 [DOCS] Add example to use 403 ErrorRedirectHandler for login redirects (thanks to serbelanalog)
• 2024-09-04 9c2d051f905 [DOCS] Convert EXT:dashboard syntax from options to confvals (thanks to Lina Wolf)
• 2024-09-04 e99f5cc0904 [BUGFIX] Allow login notification mail with f:translate VH (thanks to Mathias Brodala)
• 2024-09-04 43bc3b81f86 [DOCS] Replace reference to outdated "EditModule" in EXT:adminpanel (thanks to Garvin Hicking)
• 2024-09-04 295a9b35593 [BUGFIX] Enable search levels in RecordLinkHandler (thanks to Oliver Bartsch)
• 2024-09-04 0ca2ef073f2 [TASK] Raise phpstan/phpstan:^1.12.1 (thanks to Stefan Bürk)
• 2024-09-04 b70ce15b945 [TASK] Update Fluid to 2.15 (thanks to Simon Praetorius)
• 2024-09-02 e49f12c63df [BUGFIX] Ensure proper loading order of EXT:seo and EXT:dashboard (thanks to Garvin Hicking)
• 2024-09-02 cd806d8b566 [BUGFIX] Allow assigning empty sources to non-empty CSP directives (thanks to Oliver Hader)
• 2024-09-02 fa9a78d1807 [TASK] Allow all minor node versions in nvmrc (thanks to Benjamin Franzke)
• 2024-08-30 e764a492910 [BUGFIX] Properly redirect secondary backend module routes (thanks to Daniel Siepmann)
• 2024-08-29 1ab46cb3aed [BUGFIX] Allow to use CKEditor style definitions with an empty class (thanks to Garvin Hicking)
• 2024-08-29 84180365537 [DOCS] Fix comment in site-specific CSP disposition example (thanks to Oliver Hader)
• 2024-08-28 43cb28906c9 [TASK] Introduce Content-Security-Policy-Report-Only handling (thanks to Oliver Hader)
• 2024-08-28 f9420041d85 [BUGFIX] Prevent undefined array key exception in FlexFormValueFormatter (thanks to Torben Hansen)
• 2024-08-28 eb0ac88e04c [BUGFIX] Add aria-selected attribute to "DropDown" buttons (thanks to Christian Rath-Ulrich)
• 2024-08-27 a0d3f975a25 [DOCS] Adjust markup and remove duplication from CKEditor5 changelog (thanks to Sébastien Delcroix)
• 2024-08-27 c5e3d3956af [BUGFIX] Avoid undefined array key in Typo3tempFileService (thanks to Till Hörner)
• 2024-08-27 e6ccbe80c08 [BUGFIX] Extend exceptions thrown by Guzzle (TransferException) (thanks to Markus)
• 2024-08-27 34776fc3b6a [TASK] Upgrade used PHP 8.4 image (thanks to Stefan Bürk)
• 2024-08-27 43512139d90 [TASK] Raise phpstan/phpstan:^1.12.0 (thanks to Wouter Wolters)
• 2024-08-27 674f41d6b17 [TASK] Update to CKEditor5 v43 (thanks to Benjamin Franzke)
• 2024-08-26 656a3763c5c [DOCS] Fix YAML syntax highlighting in EXT:dashboard examples (thanks to Philipp Kuhlmay)
• 2024-08-26 fe45815ecb3 [DOCS] Update main module name for TypoScript module (thanks to Chris Müller)
• 2024-08-26 34995e75c2c [DOCS] Unify CGL of indexed_search manual (thanks to Lina Wolf)
• 2024-08-26 153230d2061 [DOCS] Document "Missing Meta Description" widget in ext:SEO (thanks to Lina Wolf)
• 2024-08-26 c8d12bc0749 [DOCS] Use createValidator() in ext:form docs (thanks to Sébastien Delcroix)
• 2024-08-23 44fc7f67faf [BUGFIX] Apply configured date format to date(time) fields (thanks to Benni Mack)
• 2024-08-23 e6e0b3ac038 [TASK] Update luxon to 3.5.0 (thanks to Andreas Kienast)
• 2024-08-23 938f31299be [BUGFIX] Allow HTML tags "mark" and "s" in RTE frontend output (thanks to Garvin Hicking)
• 2024-08-22 6882fed3bb7 [TASK] Stabilize FileClipboardCest button-click (thanks to Ayke Halder)
• 2024-08-22 82d829e3dd4 [TASK] Update lit and friends (thanks to Andreas Kienast)
• 2024-08-21 11ecb92ce1c [BUGFIX] Make Fluid DebuggerUtility css more safe against custom css (thanks to Karsten Nowak)
• 2024-08-21 4cb94e38379 [BUGFIX] Properly log renaming of resources (thanks to Oliver Bartsch)
• 2024-08-21 c8db5b5cbb1 [BUGFIX] Explicitly set icon title in record list (thanks to Oliver Bartsch)
• 2024-08-20 b5a111e4112 [BUGFIX] Fix undefined array key warnings in GifBuilder (thanks to Oliver Bartsch)
• 2024-08-20 90d22e8a26e [BUGFIX] Remove TCEforms leftovers leading to Exception (thanks to Daniel Siepmann)
• 2024-08-19 9c62ba6501c [TASK] Enhance TYPO3\CMS\Core\Type\Map capabilities (thanks to Oliver Hader)
• 2024-08-17 96472deee9e [DOCS] Update EXT:felogin Configuration listing (thanks to Lina Wolf)
• 2024-08-16 15254c52d55 [TASK] Raise doctrine/dbal:^3.9 (thanks to Stefan Bürk)
• 2024-08-16 38bce38a5f1 [DOCS] Add a hint to configure the redirect (thanks to Sandra Erbel)
• 2024-08-16 c2a38d99061 [TASK] Add accessibility ci tests with playwright/axe (thanks to Frank Naegler)
• 2024-08-15 79195cd20af [TASK] Set TYPO3 version to 12.4.20-dev (thanks to Oliver Hader)