CVE-2026-86349

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.8, 10.11.x <= 10.11.22 fail to limit the nesting depth in the server-side Markdown parser which allows an authenticated attacker to cause a denial of service (CPU resource exhaustion) via a crafted post containing deeply nested blockquotes or list items.. Mattermost Advisory ID: MMSA-2026-00707

CVSS v3 4.3 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://mattermost.com/security-updates

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-14 14:17

Updated : 2026-09-14 20:17

NVD link : CVE-2026-86349

Mitre link : CVE-2026-86349

CVE.ORG link : CVE-2026-86349

JSON object : View

Products Affected

No product.

CWE

CWE-407

Inefficient Algorithmic Complexity

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