CVE-2026-3637

Mattermost fails to enforce create_post permission when editing posts

CVSS 4.3 MEDIUMEPSS 0.2%CWE-862

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

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Affected products

Mattermost · Mattermost

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References

https://mattermost.com/security-updates