CVE-2026-50129

Mastodon: Persistent anonymous DoS via unhandled NoMethodError in MATH_TRANSFORMER

HIGH

7.5

CVSS Score

Published: June 24, 2026 at 07:50 PM UTC

Updated: June 27, 2026 at 11:42 AM UTC

1 product affected across 1 vendorMastodon

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Severity

HIGH7.5

Exploit prediction

EPSS 0.5%

SSVC

No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Mastodon · Mastodon

60%

v < 4.3.24v < 4.4.18v < 4.5.11

Affected range stops below 4.3.24, so it looks safe — our inference, not a vendor statement

Affected range stops below 4.4.18, so it looks safe — our inference, not a vendor statement

Affected range stops below 4.5.11, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

x_refsource_CONFIRM

Source: cverecord

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

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusDEFERRED

CWE

CWE-248

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