Mastodon · Mastodon · CVE-2026-23961
**Name of the Vulnerable Software and Affected Versions**
Mastodon versions 4.2.26 through 4.2.29
Mastodon versions 4.3.13 through 4.3.17
Mastodon versions 4.4.5 through 4.4.11
Mastodon versions 4.5.0 through 4.5.4
**Description**
Mastodon is a social network server that allows administrators to suspend users. Logic errors exist that can allow posts from suspended users to appear in timelines, even after suspension. Specifically, known posts from suspended users can appear if they have been boosted. In some cases, previously unknown posts from suspended users can also be processed. In certain versions, suspended users can partially bypass the suspension to post new content.
**Recommendations**
Update to Mastodon version 4.5.5.
Update to Mastodon version 4.4.12.
Update to Mastodon version 4.3.18.