← Vulnerability feed

Vulnerability record · CVE-2026-50129 · published 24 June 2026

CVE-2026-50129: Mastodon is a free, open-source social network server based on ActivityPub.

Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.11, 4.4.18, and 4.3.24, a DoS can be triggered by (Uncaught Exception vulerability), due to missing exception handling in the math sanitizer. Malformed <math> nodes can result in a DoS of a whole server or targeted users services, depending on the type of action that includes the malformed nodes and the services interacting with it. This vulnerability is fixed in 4.5.11, 4.4.18, and 4.3.24.

7.5 CVSS 3.1 High EPSS 0.46% · top 62.6% CWE-248 · CWE-248 Deferred
7.5CVSS 3.1 base score
0.46%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
1References
25 Jun 2026Last modified by NVD

Description

Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.11, 4.4.18, and 4.3.24, a DoS can be triggered by (Uncaught Exception vulerability), due to missing exception handling in the math sanitizer. Malformed <math> nodes can result in a DoS of a whole server or targeted users services, depending on the type of action that includes the malformed nodes and the services interacting with it. This vulnerability is fixed in 4.5.11, 4.4.18, and 4.3.24.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

LinkTags
https://github.com/mastodon/mastodon/security/advisories/GHSA-qrgq-9fx2-vf2r

Track CVE-2026-50129 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Source: NIST National Vulnerability Database (record CVE-2026-50129), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.