{"id":"CVE-2026-93851","title":"Path traversal in Mattermost Agents plugin mention reminder allows plugin replacement via crafted post","summary":"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 sy…","severity":"high","cvss":8,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-22"],"vendor":"Mattermost","product":"Mattermost","affected":["Mattermost >= 11.9.0 <= 11.9.1","Mattermost >= 11.8.0 <= 11.8.5","Mattermost >= 11.7.0 <= 11.7.10"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-29T00:00:00+00:00"},"published":"2026-10-28","updated":"2026-10-30","sourceUpdated":"2026-10-30T03:56:14.074Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-93851","references":[{"url":"https://mattermost.com/security-updates","label":"MMSA-2026-00742"}],"tags":["cve.org"],"epss":0.00266,"epssPercentile":0.18782,"ingestedAt":"2026-11-03T10:42:03.625Z","slug":"CVE-2026-93851","body":"## Overview\n\nMattermost 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\n\n## Affected\n\n- `Mattermost >= 11.9.0 <= 11.9.1`\n- `Mattermost >= 11.8.0 <= 11.8.5`\n- `Mattermost >= 11.7.0 <= 11.7.10`\n\n## Remediation\n\nUpdate Mattermost to versions 11.10.0, 11.9.2, 11.8.6, 11.7.11 or higher.","depth":"twilight","depthScore":44,"depthScoreParts":{"impact":44,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}