CVE-2026-96656

HighActively exploited (CISA KEV)

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.

SeverityHigh
CVSS7.2
Exploit probability—
ProductPlex Media Server
PublishedSep 23, 2026
First seenSep 23, 2026
Added to KEVOct 20, 2026
Weakness typeCWE-73CWE-73

How to fix

CISA 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.

CISA due date: Oct 23, 2026
Update
  • plex media_server1.43.3.10861 or later

Affected products

ProductAffected versionsFixed in
plex media_serverv < 1.43.3.108611.43.3.10861

Check your version

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CVE-2026-96656 · Plex Media Server · Dark Radar