CVE-2026-26230 | THREATINT

Description

Mattermost versions 10.11.x <= 10.11.10 fail to properly validate permission requirements in the team member roles API endpoint which allows team administrators to demote members to guest role. Mattermost Advisory ID: MMSA-2025-00531

PUBLISHED Reserved 2026-02-13 | Published 2026-03-16 | Updated 2026-03-17 | Assigner Mattermost

LOW: 3.8CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N

Problem types

CWE-863: Incorrect Authorization

Product status

Default status

unaffected

10.11.0 (semver)

affected

11.4.0

unaffected

10.11.11

unaffected

Credits

hackit_bharat finder

References

mattermost.com/security-updates (MMSA-2025-00531) vendor-advisory

cve.org (CVE-2026-26230)

nvd.nist.gov (CVE-2026-26230)

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