HIGH · CVSS 8.6 ACTIVELY EXPLOITED PATCH AVAILABLE

CVE-2026-96656: Plex Media Server External Control of File Name or Path Vulnerability

Facts
VendorPlex
ProductMedia Server
CVSS score8.6 · CVSS 4.0 · HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS1.8% (percentile 78)
Actively exploitedYes
Added to CISA KEV20 Oct 2026
CISA federal deadline23 Oct 2026
Weakness (CWE)CWE-73
NVD published23 Sep 2026
NVD last modified21 Oct 2026
NVD statusAnalyzed

Affected versions

ProductAffected versionsFixed in
Plex Media Serverbefore 1.43.3.108611.43.3.10861

Required action (CISA's text)

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 (NVD)

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.

SOURCES

Other Plex flaws

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 21 Oct 2026.