---
id: CVE-2026-96260
title: >-
  Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10,
  11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF
  validation of plugin requests which allows an authenticated user to exhaust
  server memory…
summary: >-
  Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10,
  11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF
  validation of plugin requests which allows an authenticated user to exhaust
  server memory…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-789
vendor: Mattermost
product: Mattermost
affected:
  - Mattermost >= 11.9.0 <= 11.9.1
  - Mattermost >= 11.8.0 <= 11.8.5
  - Mattermost >= 11.7.0 <= 11.7.10
  - Mattermost >= 11.10.0 <= 11.10.1
published: '2026-09-22'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T18:17:31.543'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-96260'
references:
  - url: 'https://mattermost.com/security-updates'
    label: responsibledisclosure@mattermost.com
tags:
  - nvd
  - cve.org
epss: 0.00411
epssPercentile: 0.32542
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-23T15:05:56.037132Z'
ingestedAt: '2026-09-22T21:11:40.323Z'
---

## Overview

Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF validation of plugin requests which allows an authenticated user to exhaust server memory and cause a denial of service via a large request body sent to a plugin endpoint.. Mattermost Advisory ID: MMSA-2026-00775

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.