---
id: CVE-2026-19600
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 sanitize authentication tokens before writing them
  to server log entries, which allows an attacker with access to server logs to
  obtain…
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 sanitize authentication tokens before writing them
  to server log entries, which allows an attacker with access to server logs to
  obtain…
severity: medium
cvss: 4.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:N/A:N'
cwe:
  - CWE-532
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: '2026-10-16'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T19:23:18.623'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-19600'
references:
  - url: 'https://mattermost.com/security-updates'
    label: responsibledisclosure@mattermost.com
tags:
  - nvd
  - cve.org
epss: 0.00236
epssPercentile: 0.14588
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-16T12:02:37.754353Z'
ingestedAt: '2026-10-16T08:02:23.122Z'
---

## 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 sanitize authentication tokens before writing them to server log entries, which allows an attacker with access to server logs to obtain valid session tokens or OAuth access tokens and impersonate authenticated users via the debug-level Mattermost server log.. Mattermost Advisory ID: MMSA-2026-00763

## Remediation

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