CVE-2026-20796
Time-of-check time-of-use vulnerability in common teams API
- State
- Published
- Severity
- 3.1 Low
- Published
- Feb 13, 2026
- Updated
- Feb 13, 2026
- Reserved
- Jan 15, 2026
Description
Mattermost versions 10.11.x <= 10.11.9 fail to properly validate channel membership at the time of data retrieval which allows a deactivated user to learn team names they should not have access to via a race condition in the /common_teams API endpoint.. Mattermost Advisory ID: MMSA-2025-00549
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 3.1 Low | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N | Mattermost |
Weaknesses
- CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
Affected Products
| Product | Versions |
|---|---|
MattermostMattermost |
|
References
- MMSA-2025-00549vendor-advisory
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.