Vulnerability 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 Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Joinmastodon | Mastodon | >= 4.4.0, < 4.4.8 |
Related Weaknesses (CWE)
References
- https://github.com/mastodon/mastodon/commit/2dc4552229b55e2e4adaef675e68ed7ae123Patch
- https://github.com/mastodon/mastodon/commit/405a49df44033e7d179f3d44d59fb68a67d5Patch
- 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
FAQ
What is CVE-2025-62605?
CVE-2025-62605 is a vulnerability with a CVSS score of 4.3 (MEDIUM). 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 attacke...
How severe is CVE-2025-62605?
CVE-2025-62605 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-62605?
Check the references section above for vendor advisories and patch information. Affected products include: Joinmastodon Mastodon.