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CVE-2026-93851

Path traversal in Mattermost Agents plugin mention reminder allows plugin replacement via crafted post

CVSS score

8.0

EPSS probability

—

Risk score

0.8

Published

2 h ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Patch status has not yet been verified

Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.

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Vulnerability description

DayBreach AI Explanation

Verified against sources

Mattermost Agents Plugin Path Traversal Vulnerability

Sources read

1

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

Mattermost versions fail to validate the target post ID in the Agents plugin's mention reminder component. This allows an authenticated user to replace an installed plugin and execute code on the server via a crafted post.

Why does it matter?

It matters because it allows a low-privileged user to achieve code execution on the server via system administrator interaction, creating a high severity risk.

What should be done?

  • Follow the vendor security advisory
  • Review unaffected versions
  • Apply updates
Chain of evidence and sources2 verified claims

Mattermost sürümleri 11.9.x, 11.8.x ve 11.7.x aralıklarındaki belirli sürümlerde Agents eklentisinin hatırlatıcı bileşeninde hedef gönderi kimliği doğrulanmamaktadır.

S0 · daybreach-canonicalS1 · cvelist

Yararlanma, sistem yöneticisinin tıkladığı sahte hatırlatıcı içeren hazırlanmış bir gönderi yoluyla eklenti değişimine ve sunucuda kod çalıştırmaya yol açar.

S0 · daybreach-canonicalS1 · cvelist
Show the technical text from the sources

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 vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H

CWE: CWE-22

This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-93851 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1mattermostMattermost View
Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
8.0CVSS V31HIGHCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:HNVD
8.0CVSS V3_1HIGHCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:HCVE CNA

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-93851 is associated with the following CWEs:

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-93851 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsLow
UserGerekiyor

Official Sources and Advisories

MMSA-2026-00742vendor-advisory

CVSS Vector Radar Chart

8.0 / 10
Attack VectorNetworkComplexityHighPrivilegesLowUser Interact.RequiredConfidentialityHighIntegrityHighAvailabilityHigh

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H
Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredLow privileges
User Interaction—
Confidentiality (Gizlilik)High
Integrity (Bütünlük)High
Availability (Erişilebilirlik)High

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Follow the vendor

M
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Weakness Type (CWE & CAPEC)

CWE-22

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CVE-2026-93851 · Path traversal in Mattermost Agents plugin…