CSRF Vulnerability in Mattermost Plugin for Authenticated Users
CVE-2026-96260

6.5MEDIUM

Key Information:

Vendor

Mattermost
Status
Mattermost
Vendor
CVE Published:
22 September 2026

What is CVE-2026-96260?

Mattermost versions up to 11.10.1 have a vulnerability that fails to enforce a limit on the request body size during CSRF validation for plugin requests. This oversight allows authenticated users to exploit the vulnerability by sending oversized requests to plugin endpoints, potentially exhausting server memory and leading to service disruption.

Affected Version(s)

Mattermost 11.9.0 <= 11.9.1

Mattermost 11.8.0 <= 11.8.5

Mattermost 11.7.0 <= 11.7.10

References

https://mattermost.com/security-updates
vendor-advisory

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

alimursaliyev
.