VDB
CVE-2026-16049
CVE-2026-16049
PUBLISHED
CVSS 3.9 LOW
Reported by Mattermost · Published August 17, 2026
Mattermost Plugins versions <=11.8 10.20.11 11.5.7.0 _The Mattermost GitLab plugin fails to verify channel permissions when processing API requests with a caller-supplied_ {{post_id}}_, and fails to validate the_ {{web_url}} _parameter against the configured GitLab instance, which allows an authenticated attacker to inject bot-authored messages containing arbitrary URLs into channels they do not have access to via the_ {{createIssue}} _and_ {{attachCommentToIssue}} _API endpoints._ Mattermost Advisory ID: MMSA-2026-00673
Risk Scores
CVSS 3.1
3.9
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mattermost | Mattermost | 0, 0, 11.9.0 |
| Mattermost | Mattermost | 0, 0, 11.9.0 |
Timeline
- Aug 17, 2026 CVE Published
- Aug 18, 2026 CVE Updated
- Aug 22, 2026 Coalition ESS Score
- Aug 24, 2026 EPSS Score
References
- MMSA-2026-00673 vendor-advisory