Path traversal in Mattermost Agents plugin mention reminder allows plugin replacement via crafted post
Summary
| CVE | CVE-2026-93851 |
|---|---|
| State | PUBLISHED |
| Assigner | Mattermost |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-28 22:17:17 UTC |
| Updated | 2026-10-30 04:18:30 UTC |
| 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 |
Risk And Classification
Primary CVSS: v3.1 8 HIGH from [email protected]
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H
EPSS: 0.002660000 probability, percentile 0.188140000 (date 2026-10-30)
Problem Types: CWE-22 | CWE-22 CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 8 | HIGH | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 8 | HIGH | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
LowUser Interaction
RequiredScope
ChangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Mattermost | Mattermost | affected 11.9.0 11.9.1 semver | Not specified |
| CNA | Mattermost | Mattermost | affected 11.8.0 11.8.5 semver | Not specified |
| CNA | Mattermost | Mattermost | affected 11.7.0 11.7.10 semver | Not specified |
| CNA | Mattermost | Mattermost | unaffected 11.10.0 | Not specified |
| CNA | Mattermost | Mattermost | unaffected 11.9.2 | Not specified |
| CNA | Mattermost | Mattermost | unaffected 11.8.6 | Not specified |
| CNA | Mattermost | Mattermost | unaffected 11.7.11 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| mattermost.com/security-updates | [email protected] | mattermost.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: z01dberg (en)
Additional Advisory Data
Solutions
CNA: Update Mattermost to versions 11.10.0, 11.9.2, 11.8.6, 11.7.11 or higher.
There are currently no legacy QID mappings associated with this CVE.