CVE-2026-4055
Low
No strong exploitation signal.
CVSS base
4.3
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
EPSS — probability of exploitation (30 days)
0.2%
4.7th percentile
CISA KEV
Not listed
Weakness / dates
CWE-863
Published 2026-05-21 · modified 2026-07-23
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | N | None |
| Integrity | L | Low |
| Availability | N | None |
Timeline
- 2026-05-21 — Published (NVD)
- 2026-07-23 — Last modified (NVD)
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