Cloudanix VulnDB

CVE-2026-16049

Medium · 4.3

CVSS

4.3

EPSS

0.3%

Published

Aug 17, 2026

CISA due date

—

The record

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

Affected packages

Ecosystem Package Introduced Fixed

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