High 8.0Published Oct 28, 2026

CVE-2026-93851Path traversal in Mattermost Agents plugin mention reminder allows plugin replacement via crafted post

Updated under an hour ago (Oct 30, 2026, 12:50 AM ET)

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EPSS puts the chance of exploitation in the next 30 days at 0.27%, higher than 19% of scored CVEs.

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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

CVSS: 8.0 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-22
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.27% (percentile 19)
Assigned by: Mattermost
NVD analysis: Awaiting Analysis
Record last updated: Oct 29, 2026
First seen by InfoSec Signals: Oct 28, 2026

Affected products

Affected products

Mattermost Mattermost mattermost:mattermost (from the name)	from 11.9.0 through 11.9.1; from 11.8.0 through 11.8.5; from 11.7.0 through 11.7.10; 11.10.0 not affected; 11.9.2 not affected; 11.8.6 not affected; 11.7.11 not affected	CNA record

References

References

https://mattermost.com/security-updates	vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.