CVE-2026-93851 Path traversal in Mattermost Agents plugin mention reminder allows plugin replacement via crafted post
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-93851?
CVE-2026-93851 is a high-severity vulnerability in Mattermost, published on 28 Oct 2026.
Official description
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component, which allows an authenticated user who can post in a channel visible to a system administrator to cause the administrator's browser to send an unintended API request, resulting in replacement of an installed plugin and code execution on the server, via a crafted post containing a forged mention reminder that the administrator clicks. Mattermost Advisory ID: MMSA-2026-00742
Weakness: CWE-22
Which versions are affected by CVE-2026-93851?
How do I fix CVE-2026-93851?
No fix has been published for CVE-2026-93851 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-93851 being exploited?
There is no known exploitation of CVE-2026-93851 in the wild and no public exploit code.
Sources
Also known as GHSA-jq9q-vph7-fh8w.