Mattermost Incorrect Authorization vulnerability in github.com/mattermost/mattermost
Mattermost Incorrect Authorization vulnerability in github.com/mattermost/mattermost
02 / AFFECTED SOFTWARE
Affected packages
44 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint
Mattermost Incorrect Authorization vulnerability in github.com/mattermost/mattermost
Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API, which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint.
05 / REFERENCES
Further evidence
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/11xxx/CVE-2025-11777.json
- https://mattermost.com/security-updates
- https://nvd.nist.gov/vuln/detail/CVE-2025-11777
- https://github.com/advisories/GHSA-mqcj-8c2g-h97q
- https://github.com/mattermost/mattermost/commit/98acefe911dd9de7edf47a7d825dd99f53141a52
- https://github.com/mattermost/mattermost/commit/ba86dfc5876b354b9d3c20ff45c08ca6f8426149
- https://github.com/mattermost/mattermost/commit/d72d437f1567ba0b639b6e4fd73bab06c51baab5
- https://github.com/mattermost/mattermost