Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows a…

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

1. May 18, 2026 · NIST NVD

   Detected

   Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627

2. Oct 14, 2026 · NIST NVD

   Updated

   Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627

Affected

• cpe mattermost/mattermost serverversion unspecified

Sources

• CVE.orgVulnerability recordCVE-2026-3637

  Official CVE identifier

  cve.org
• FIRST EPSSExploitation probabilityCVE-2026-3637

  30-day exploitation probability 0.3%

  first.org
• NIST NVDVulnerability recordCVE-2026-3637

  Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests t

  nvd.nist.gov

References

• Vendor Advisory · mattermost.com