CVSS 3.1
4.6 mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:NCVE-2026-27659
Medium (4.6) in mattermost mattermost server. EPSS 0.1% chance of exploitation in the next 30 days. Fixed in github.com/mattermost/mattermost/server/v8 10.11.11, 11.2.3, 11.3.2.
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to properly validate CSRF tokens in the /api/v4/access_control_policies/{policy_id}/activate endpoint, which allows an attacker to trick an admin into changing access control policy active status via a crafted request.. Mattermost Advisory ID: MMSA-2026-00578
Severity
- EPSS
- 0.1% chance of exploitation in the next 30 days; higher than 2% of CVEs (scores of 2026-10-31)
- CWE
- CWE-352
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mattermost:mattermost_server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-rmhw-c3xr-m3xx | Go | github.com/mattermost/mattermost/server/v8 | >=11.4.0-rc1 <11.4.1 | 11.4.1 |
| GHSA-rmhw-c3xr-m3xx | Go | github.com/mattermost/mattermost/server/v8 | >=11.3.0-rc1 <11.3.2 | 11.3.2 |
| GHSA-rmhw-c3xr-m3xx | Go | github.com/mattermost/mattermost/server/v8 | >=11.2.0-rc1 <11.2.3 | 11.2.3 |
| GHSA-rmhw-c3xr-m3xx | Go | github.com/mattermost/mattermost/server/v8 | >=10.11.0-rc1 <10.11.11 | 10.11.11 |
| GHSA-rmhw-c3xr-m3xx | Go | github.com/mattermost/mattermost/server/v8 | >=8.0.0-20260105080200-d27a2195068d <10.11.11 | 10.11.11 |
| GO-2026-5629 | Go | github.com/mattermost/mattermost-server | >=10.11.0-rc1+incompatible <10.11.11+incompatible >=11.2.0-rc1+incompatible <11.2.3+incompatible >=11.3.0-rc1+incompatible <11.3.2+incompatible >=11.4.0-rc1+incompatible <11.4.1+incompatible | 10.11.11+incompatible, 11.2.3+incompatible, 11.3.2+incompatible, 11.4.1+incompatible |
| GO-2026-5629 | Go | github.com/mattermost/mattermost-server/v5 | all versions | no fix published |
| GO-2026-5629 | Go | github.com/mattermost/mattermost-server/v6 | all versions | no fix published |
| GO-2026-5629 | Go | github.com/mattermost/mattermost/server/v8 | >=8.0.0-20260105080200-d27a2195068d | no fix published |