CVSS 3.1
3.1 lowCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:NCVE-2026-20796
Low (3.1) in mattermost mattermost server. EPSS 0.2% chance of exploitation in the next 30 days. Fixed in github.com/mattermost/mattermost-server 10.11.10, 10.11.10+incompatible.
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
Severity
- EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 12% of CVEs (scores of 2026-10-31)
- CWE
- CWE-367
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mattermost:mattermost_server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-2xf7-hmf6-p64j | Go | github.com/mattermost/mattermost-server | >=10.11.0 <10.11.10 | 10.11.10 |
| GO-2026-4495 | Go | github.com/mattermost/mattermost-server | >=10.11.0+incompatible <10.11.10+incompatible | 10.11.10+incompatible |