Plex Media Server External Control of File Name or Path Vulnerability
This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run Media Server, fix it now.
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.
US federal civilian agencies must remediate by Oct 23, 2026.
No official fix confirmed yet
Until a fix ships, follow the vendor's mitigations and CISA's required action, limit exposure of affected systems, and watch this record for a patch.
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.
Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.
| Product | Vendor | Affected versions | Fixed in | Source |
|---|---|---|---|---|
| Media Server | Plex | < 1.43.0.10861 | 1.43.0.10861 | KEV |
Sources: KEV = CISA Known Exploited Vulnerabilities catalog.
Developments from the last 30 days, newest first.
CVE-2026-96656 scored CVSS 8.6: Plex Media Server, Plex Media Server External Control of File Name or Path Vulnerability
CISA lists this as exploited in the wild. Unpatched Media Server systems are exposed to active attacks now.
Basis: NIST National Vulnerability Database
CVE-2026-96656 added to CISA KEV: Plex Media Server, Plex Media Server External Control of File Name or Path Vulnerability
CISA lists this as exploited in the wild. Unpatched Media Server systems are exposed to active attacks now.
Basis: CISA Known Exploited Vulnerabilities catalog
CISA lists this as exploited in the wild. Unpatched Media Server systems are exposed to active attacks now.
Apply the vendor's security update for Media Server.
CISA lists this as exploited in the wild. Unpatched SiteGuard Server Edition and Media Server systems are exposed to active attacks now.
Apply the vendor's security update for SiteGuard Server Edition and Media Server.
