CVE-2026-96656

Plex Media Server

Published 23 Sept 2026 · updated 20 Oct 2026 · Modified

8.6 High · CVSS 4.0, CNA

Exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on 20 Oct 2026, with a remediation deadline of 23 Oct 2026 for US federal agencies.

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.

Description

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.

References