Headline
GHSA-9r42-rhw3-2222: Mattermost is vulnerable to CPU exhaustion via crafted HTTP request
Mattermost versions 10.11.x <= 10.11.8 fail to validate input size before processing hashtags which allows an authenticated attacker to exhaust CPU resources via a single HTTP request containing a post with thousands space-separated tokens.
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- GitHub Advisory Database
- GitHub Reviewed
- CVE-2025-14822
Mattermost is vulnerable to CPU exhaustion via crafted HTTP request
Low severity GitHub Reviewed Published Jan 16, 2026 to the GitHub Advisory Database • Updated Jan 16, 2026
Package
gomod github.com/mattermost/mattermost-server (Go)
Affected versions
>= 10.11.0, <= 10.11.8
>= 11.0.0, < 11.2.0
Patched versions
10.11.9
11.2.0
gomod github.com/mattermost/mattermost/server/v8 (Go)
< 8.0.0-20251201064648-4d86263f5430
8.0.0-20251201064648-4d86263f5430
Description
Published to the GitHub Advisory Database
Jan 16, 2026
Last updated
Jan 16, 2026