Moderate severityNVD Advisory· Published Mar 25, 2026· Updated Mar 25, 2026
CSRF vulnerability in UpdateAccessControlPolicyActiveStatus endpoint
CVE-2026-27659
Description
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
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
github.com/mattermost/mattermost/server/v8Go | >= 11.4.0-rc1, < 11.4.1 | 11.4.1 |
github.com/mattermost/mattermost/server/v8Go | >= 11.3.0-rc1, < 11.3.2 | 11.3.2 |
github.com/mattermost/mattermost/server/v8Go | >= 11.2.0-rc1, < 11.2.3 | 11.2.3 |
github.com/mattermost/mattermost/server/v8Go | >= 10.11.0-rc1, < 10.11.11 | 10.11.11 |
github.com/mattermost/mattermost/server/v8Go | >= 8.0.0-20260105080200-d27a2195068d, < 10.11.11 | 10.11.11 |
Affected products
1- Range: 11.2.0
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
3- github.com/advisories/GHSA-rmhw-c3xr-m3xxghsaADVISORY
- mattermost.com/security-updatesghsavendor-advisoryWEB
- nvd.nist.gov/vuln/detail/CVE-2026-27659ghsaADVISORY
News mentions
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