Actively exploited in the wild
Plex Media Server External Control of File Name or Path Vulnerability
Plex - Media Server · Listed in the CISA KEV since 2026-10-20. This indicates confirmed attacks in production environments.
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CVE-2026-96656
HighCVSS 7.2KEVExploitation Probability (EPSS)
Low risk32th percentile - higher than 32% of all known CVEs
Summary
Plex Media Server before 1.43.3.10861 allows an admin user to write arbitrary files that may be executed on load. The preference TranscoderH264Options is appended verbatim to x264's option string on every transcode. At startup, all .so files are run without signature, execute bit, or symbol checks.
Risk Assessment
Risk of arbitrary code execution by an administrator, potentially leading to full compromise of the Plex server and system.
Recommendation
Update Plex Media Server to version 1.43.3.10861 or later. Restrict trust in administrators and monitor .so files.
Other vulnerabilities in Plex Media Server
See all- CVE-2014-9304High
Plex Media Server before version 0.9.9.3 allows remote attackers to bypass the web server whitelist, conduct SSRF attacks, and execute arbitrary administrative actions via multiple crafted X-Plex-Url headers to system/proxy, which are inconsistently processed by the request handler in the backend web server.
- CVE-2026-96655MediumActively exploited
Plex Media Server before 1.43.3.10861 allows an authenticated user to request arbitrary internal or external addresses via the '/video/:/transcode/universal' path parameter.
- CVE-2026-96654MediumActively exploited
Plex Media Server before 1.43.3.10861 does not correctly neutralize URL values included in 'searchOne,' allowing an attacker to call other plugins' functions and supply their own parameters.
- CVE-2026-96652MediumActively exploited
Plex Media Server before 1.43.3.10861 allows SSRF via '/player/timeline'. An attacker using any X-Plex-Token value can include a full URL in the 'protocol' parameter and force the Plex server to POST to the attacker's chosen destination.
- CVE-2020-5741HighActively exploited
Deserialization of Untrusted Data in Plex Media Server on Windows allows a remote, authenticated attacker to execute arbitrary Python code.
- CVE-2026-96651Medium
Plex Media Server before 1.43.3.10861 suffers from path traversal in '/system/agents/media/get' due to insufficient validation of the url parameter. An attacker with a valid session token can read arbitrary files accessible to the server user, including the PlexOnlineToken that grants full control.
- CVE-2025-69417Medium
In the plex.tv backend for Plex Media Server (PMS) through 2025-12-31, a non-server device token can retrieve share tokens (intended for unrelated access) via a shared_servers endpoint.
- CVE-2025-69416Medium
In the plex.tv backend for Plex Media Server (PMS) through 2025-12-31, a non-server device token can retrieve other tokens (intended for unrelated access) via clients.plex.tv/devices.xml.
Original NVD description (English source)
Plex Media Server before 1.43.3.10861 allows an admin user to write arbitrary files that may be executed on load. The preference TranscoderH264Options is appended verbatim to x264's option string on every transcode. At startup, all .so files are run without signature, execute bit, or symbol checks.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS