CVE-2026-23962Mastodon is a free, open-source social network server based on ActivityPub.
Updated under an hour ago ()
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It affects joinmastodon mastodon. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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
- 7.5 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-770
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Jun 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
joinmastodon mastodon joinmastodon:mastodon | before 4.3.18; from 4.4.0 before 4.4.12; from 4.5.0 before 4.5.5 | NVD |
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
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.