CVE-2026-93851
Path traversal in Mattermost Agents plugin mention reminder allows plugin replacement via crafted post
No known exploitation. EPSS puts it in the 19th percentile. Fixed versions are out.
What to do
Find your product and version, then upgrade to the build on the right.
- MattermostAffected: ≥ 11.9.0, ≤ 11.9.1Upgrade to: after 11.9.1Affected: ≥ 11.8.0, ≤ 11.8.5Upgrade to: after 11.8.5Affected: ≥ 11.7.0, ≤ 11.7.10Upgrade to: after 11.7.10Fixed builds11.10.0, 11.9.2, 11.8.6, 11.7.11Stated by: CVE record
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
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
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.3% chance of exploitation activity in the next 30 days, which ranks it in the 19th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
11 events over 2 days, from the signal feeds we watch.
- Patch availablerecord updated
- Patch availablepatch available, record updated, record updated
- Patch availablepublished, weakness classified, att&ck mapped, record updated
Affected products
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H
Scored 8.0 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
- Privileges Required LowRequires basic user-level privileges
- User Interaction RequiredA user must click a link, open a file, or perform some action
Scope
- Scope ChangedThe exploit can affect other components (e.g. sandbox escape, host compromise from VM)
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
Sources
References in the record
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