Vulnerability Description
Mastodon is a free, open-source social network server based on ActivityPub. Mastodon versions before v4.3.18, v4.4.12, and v4.5.5 do not have a limit on the maximum number of poll options for remote posts, allowing attackers to create polls with a very large amount of options, greatly increasing resource consumption. Depending on the number of poll options, an attacker can cause disproportionate resource usage in both Mastodon servers and clients, potentially causing Denial of Service either server-side or client-side. Mastodon versions v4.5.5, v4.4.12, v4.3.18 are patched.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Joinmastodon | Mastodon | < 4.3.18 |
Related Weaknesses (CWE)
References
- https://github.com/mastodon/mastodon/releases/tag/v4.3.18Release Notes
- https://github.com/mastodon/mastodon/releases/tag/v4.4.12Release Notes
- https://github.com/mastodon/mastodon/releases/tag/v4.5.5Release Notes
- https://github.com/mastodon/mastodon/security/advisories/GHSA-gg8q-rcg7-p79gVendor Advisory
FAQ
What is CVE-2026-23962?
CVE-2026-23962 is a vulnerability with a CVSS score of 7.5 (HIGH). Mastodon is a free, open-source social network server based on ActivityPub. Mastodon versions before v4.3.18, v4.4.12, and v4.5.5 do not have a limit on the maximum number of poll options for remote p...
How severe is CVE-2026-23962?
CVE-2026-23962 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-23962?
Check the references section above for vendor advisories and patch information. Affected products include: Joinmastodon Mastodon.