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CVE

CVE-2026-23962

Mastodon vulnerable to Denial of Service from a single post (client/server)
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CVE

CVE-2026-23962

Mastodon vulnerable to Denial of Service from a single post (client/server)

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.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
7.5
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
C
H
U
0
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
C
H
U
-

Related Resources

No items found.

References

https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23962.json, https://github.com/mastodon/mastodon/releases/tag/v4.3.18, https://github.com/mastodon/mastodon/releases/tag/v4.4.12, https://github.com/mastodon/mastodon/releases/tag/v4.5.5, https://github.com/mastodon/mastodon/security/advisories/GHSA-gg8q-rcg7-p79g, https://nvd.nist.gov/vuln/detail/CVE-2026-23962

Severity

7.5

CVSS Score
0
10

Basic Information

Ecosystem
Base CVSS
7.5
EPSS Probability
0.0002%
EPSS Percentile
0.05054%
Introduced Version
0,69e14246b838443985a541e97327494b8d2fdffb
Fix Available
fa553d848417ffe48f23794f7b798b87eb57477f,cbb10858555d3cbfde24d52859e2d690526c8173

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