We just released Mastodon 4.3.6, 4.2.19 and 4.1.24. They contain important security fixes.
We recommend server administrators to update as soon as possible if they use SAML, or are on the development version.
If you are using our nightly releases, a container image with the fix has been published with the nightly.2025-03-14-security tag.
Full release notes and update instructions are available on our GitHub release page: