CVE-2026-2462 Admin RCE via Malicious Plugin Upload on CI Test Instances
An unauthenticated attacker can achieve remote code execution and steal credentials by uploading a malicious plugin to CI test instances with default admin credentials.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-2462?
CVE-2026-2462 is a medium-severity vulnerability in Mattermost Mattermost Server, published on 16 Mar 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to restrict plugin installation on CI test instances with default admin credentials which allows an unauthenticated attacker to achieve remote code execution and exfiltrate sensitive configuration data including AWS and SMTP credentials via uploading a malicious plugin after changing the import directory. Mattermost Advisory ID: MMSA-2025-00528
Weakness: CWE-863
Which versions are affected by CVE-2026-2462?
It affects 1 product.
Products include Mattermost Mattermost Server.
How do I fix CVE-2026-2462?
No fix has been published for CVE-2026-2462 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-2462 being exploited?
There is no known exploitation of CVE-2026-2462 in the wild and no public exploit code.
Other vulnerabilities in Mattermost Mattermost Server
- CVE-2025-12419 Account takeover on OAuth/OpenID-enabled servers
- CVE-2025-12421 Account Takeover via Code Exchange Endpoint
- CVE-2025-4981 Path Traversal Leading to RCE by Any Authenticated Mattermost User
- CVE-2025-20051 Arbitrary file read via block duplication in Mattermost Boards
- CVE-2025-25279 Arbitrary file read in Mattermost Boards via import & export board archive
Sources
Also known as GHSA-fprx-ppqr-8wgf.