CVE-2025-6226

Description

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.

Affected packages (6)

• Go/github.com/mattermost/mattermost-server>= 10.5.0, < 10.5.7
• Go/github.com/mattermost/mattermost-server>= 9.11.0+incompatible, < 9.11.17+incompatible, >= 10.5.0+incompatible, < 10.5.7+incompatible, >= 10.7.0+incompatible, < 10.7.4+incompatible, >= 10.8.0+incompatible, < 10.8.2+incompatible
• Go/github.com/mattermost/mattermost-server/v5from 0
• Go/github.com/mattermost/mattermost-server/v6from 0
• Go/github.com/mattermost/mattermost/server/v8from 0, < 8.0.0-20250520130510-fa40a8c5d47f
• Go/github.com/mattermost/mattermost/server/v8from 0, < 8.0.0-20250520130510-fa40a8c5d47f

CVSS scores

References (5)

• ADVISORYhttps://github.com/advisories/GHSA-7h34-9chr-58qh
• ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2025-6226
• PATCHhttps://github.com/mattermost/mattermost
• WEBhttps://github.com/mattermost/mattermost/commit/fa40a8c5d47fed5c166429a1c1bd95d62b241d89
• WEBhttps://mattermost.com/security-updates