Mattermost Missing Authentication for Critical Function in github.com/mattermost/mattermost-server
Mattermost Missing Authentication for Critical Function in github.com/mattermost/mattermost-server
02 / AFFECTED SOFTWARE
Affected packages
74 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
Mattermost Missing Authentication for Critical Function in github.com/mattermost/mattermost-server
Mattermost versions 10.5.x <= 10.5.6, 10.8.x <= 10.8.1, 10.7.x <= 10.7.3, 9.11.x <= 9.11.16 fail to verify authorization when retrieving cached posts by PendingPostID which allows an authenticated user to read posts in private channels they don't have access to via guessing the PendingPostID of recently created posts.
Mattermost versions 10.5.x <= 10.5.6, 10.8.x <= 10.8.1, 10.7.x <= 10.7.3, 9.11.x <= 9.11.16 fail to verify authorization when retrieving cached posts by PendingPostID which allows an authenticated user to read posts in private channels they don't have access to via guessing the PendingPostID of recently created posts.
05 / REFERENCES
Further evidence
- https://github.com/advisories/GHSA-7h34-9chr-58qh
- https://github.com/mattermost/mattermost/commit/fa40a8c5d47fed5c166429a1c1bd95d62b241d89
- https://mattermost.com/security-updates
- https://nvd.nist.gov/vuln/detail/CVE-2025-6226
- https://github.com/mattermost/mattermost
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/6xxx/CVE-2025-6226.json