CVE-2025-62605
In Mastodon version 4.4, support for verifiable quote posts with quote controls was added, but it is possible for an attacker to bypass these controls in Mastodon versions prior to 4.4.8 and 4.5.0-beta.2.
Does this matter?
Lower severity and a low EPSS score (0.27%). Track it; it rarely justifies an emergency change on its own.
Description
Mastodon is a free, open-source social network server based on ActivityPub. In Mastodon version 4.4, support for verifiable quote posts with quote controls was added, but it is possible for an attacker to bypass these controls in Mastodon versions prior to 4.4.8 and 4.5.0-beta.2. Mastodon internally treats reblogs as statuses. Since they were not special-treated, an attacker could reblog any post, then quote their reblog, technically quoting themselves, but having the quote feature a preview of the post they did not get authorization for with all of the affordances that would be otherwise denied by the quote controls. This issue has been patched in versions 4.4.8 and 4.5.0-beta.2.
- CVSS 3.1
- 4.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 0.27% probability · 18th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-754
- Affected
- joinmastodon/mastodon
- Source
- security-advisories@github.com
References
- https://github.com/mastodon/mastodon/commit/2dc4552229b55e2e4adaef675e68ed7ae123d78ePatch
- https://github.com/mastodon/mastodon/commit/405a49df44033e7d179f3d44d59fb68a67d54789Patch
- https://github.com/mastodon/mastodon/releases/tag/v4.4.8Release Notes
- https://github.com/mastodon/mastodon/releases/tag/v4.5.0-beta.2Release Notes
- https://github.com/mastodon/mastodon/security/advisories/GHSA-8h43-rcqj-wpc6Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.