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Description

Mattermost versions 11.5.x <= 11.5.1 fail to validate team-level run_create permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request. Mattermost Advisory ID: MMSA-2026-00629

PUBLISHED Reserved 2026-03-12 | Published 2026-05-21 | Updated 2026-05-21 | Assigner Mattermost




MEDIUM: 4.3CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Problem types

CWE-863: Incorrect Authorization

Product status

Default status
unaffected

11.5.0 (semver)
affected

11.6.0
unaffected

11.5.2
unaffected

10.11.14
unaffected

11.4.4
unaffected

Credits

0x7oda7123 finder

References

mattermost.com/security-updates (MMSA-2026-00629) vendor-advisory

cve.org (CVE-2026-4055)

nvd.nist.gov (CVE-2026-4055)

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