CVE-2026-50129
Mastodon: Persistent anonymous DoS via unhandled NoMethodError in MATH_TRANSFORMER
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.
INFO
Published Date :
June 24, 2026, 9:16 p.m.
Last Modified :
June 25, 2026, 4:32 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Mastodon to version 4.5.11 or later.
- Update Mastodon to version 4.4.18 or later.
- Update Mastodon to version 4.3.24 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-50129.
| URL | Resource |
|---|---|
| https://github.com/mastodon/mastodon/security/advisories/GHSA-qrgq-9fx2-vf2r |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-50129 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-50129
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-50129 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-50129 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 25, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-50129', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-25T13:25:34.635259Z'} -
New CVE Received by [email protected]
Jun. 24, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'mastodon', 'product': 'mastodon', 'versions': [{'status': 'affected', 'version': '>= 4.5.0-beta.1, < 4.5.11'}, {'status': 'affected', 'version': '>= 4.4.0-beta.1, < 4.4.18'}, {'status': 'affected', 'version': '< 4.3.24'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-248 Added Reference https://github.com/mastodon/mastodon/security/advisories/GHSA-qrgq-9fx2-vf2r