VULNERABILITY INTELLIGENCE
CVE-2026-16049
CVSS score4.3 MEDIUM
EPSS probability0.29%
CISA KEVNot currently listed
Published2026-08-17
Last modified2026-08-18
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Description
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
Weakness classification
- responsibledisclosure@mattermost.com: CWE-862