CVE-2026-33869

Name of the Vulnerable Software and Affected Versions Mastodon versions 4.5.0 through 4.5.7 Mastodon versions 4.4.0 through 4.4.14

Description Mastodon is a free, open-source social network server based on ActivityPub. An attacker who is aware of a quote before it has reached a server can prevent the quote from being correctly processed on that server. This issue affects versions 4.5.x prior to 4.5.8 and 4.4.x prior to 4.4.15. Versions 4.3 and earlier are not affected as they do not support quotes.

Recommendations Update Mastodon to version 4.5.8 or later. Update Mastodon to version 4.4.15 or later.