Vulnerability · Published Apr 15, 2026 · Assigned by Mattermost
CVE-2026-28741CSRF Protection Bypass Allows Updating a User's Authentication Method
Medium 6.8
In plain English
A medium-severity cross-site request forgery in Mattermost from Mattermost. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to validate CSRF tokens on an authentication endpoint which allows an attacker to update a user's authentication method via a CSRF attack by tricking a user into visiting a malicious page. Mattermost Advisory ID: MMSA-2026-00625
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | 11.3.3+incompatible, 11.4.3+incompatible, 11.5.0+incompatible | GO-2026-5495 |
| Go | github.com/mattermost/mattermost-server/v5 | no fix listed | GO-2026-5495 |
| Go | github.com/mattermost/mattermost-server/v6 | no fix listed | GO-2026-5495 |
| Go | github.com/mattermost/mattermost/server/v8 | 11.3.3 | GHSA-m7cf-4gh2-v4qg |
| Go | github.com/mattermost/mattermost/server/v8 | 8.0.0-20260220133927-c29cf05d40f8 | GHSA-m7cf-4gh2-v4qg |
| Go | github.com/mattermost/mattermost/server/v8 | 8.0.0-20260220133927-c29cf05d40f8 | GO-2026-5495 |
| Go | github.com/mattermost/mattermost/server/v8 | 11.5.0 | GHSA-m7cf-4gh2-v4qg |
| Go | github.com/mattermost/mattermost/server/v8 | 11.4.3 | GHSA-m7cf-4gh2-v4qg |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mattermost | Mattermost | 10.11.0 – through 10.11.1211.5.0 – through 11.5.011.4.0 – through 11.4.211.3.0 – through 11.3.2 |
Weakness: CWE-352 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
References
- MMSA-2026-00625 vendor-advisory