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Back to active CVEs
High · CVSS 8.0CVE-2026-93851

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

Answer in brief

CVE-2026-93851 records a High severity (CVSS 8.0) vulnerability in Path traversal in Mattermost Agents plugin mention reminder allows plugin replacement via crafted post. The current sources do not mark it as known exploited. The current feed maps Mattermost/Mattermost (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 28, 2026Updated Oct 28, 2026Source checked Oct 28, 2026First seen by HOL Oct 28, 2026Material review Oct 28, 2026
Upstream Advisory

Key facts

Risk
High · CVSS 8.0
Exploitation
Not marked as known exploited
Affected software
1 mapped package or product
Fix availability
Not reported

Why this deserves its current priority

CVSS is 8.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Mattermost/Mattermost (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
PackageAffected rangeFixed version
Mattermost/Mattermostgeneric>=11.9.0 <=11.9.1 || >=11.8.0 <=11.8.5 || >=11.7.0 <=11.7.10Not reported

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for Mattermost/Mattermost.
  2. 2Review the reported fix. Source-reported solution: Update Mattermost to versions 11.10.0, 11.9.2, 11.8.6, 11.7.11 or higher.

Evidence timeline and material changes

  1. Published upstream

    Oct 28, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  2. Source modified

    Oct 28, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  3. First seen by HOL

    Oct 28, 2026

Sources and claim methodology

  • Source referencemattermost.com
Upstream source 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

Quoted source text, attributed separately from HOL analysis.

Related CVEs

  • LangGraph: Unencoded identifiers in LangGraph SDK v3 streaming can redirect authenticated GET requestsAlso CWE-22
  • gopass before 1.17.0 Path Traversal via fs Storage Prune and IsDirAlso CWE-22
  • Domoticz: Missing authorization and path traversal in the udevices Lua parser handlerAlso CWE-22

Record context

Vulnerability class
Path Traversal
EPSS
Not reported
CWE IDs
CWE-22
Source
CVE List V5
Source checked
Oct 28, 2026
References
1 linked source
Open source record