All vulnerabilities
CVE-2026-19600

Mattermost logs plaintext authentication tokens in debug-level server logs on failed auth attempts

Mattermost MattermostApplications & CMS
Open in ThreatlineRecord JSON
CVSS
4.5Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.24%Chance of exploitation activity in the next 30 days, higher than 13% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published16 Oct 2026Updated 16 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Description

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

Text from CVE List

Affected versions 9

  • Mattermostaffected: 11.9.0 through 11.9.1CVE List
  • Mattermostaffected: 11.8.0 through 11.8.5CVE List
  • Mattermostaffected: 11.7.0 through 11.7.10CVE List
  • Mattermostaffected: 11.10.0 through 11.10.1CVE List
  • Mattermostunaffected: 11.11.0CVE List
  • Mattermostunaffected: 11.9.2CVE List
  • Mattermostunaffected: 11.8.6CVE List
  • Mattermostunaffected: 11.7.11CVE List
  • Mattermostunaffected: 11.10.2CVE List

References 1