CVE-2026-96656
high CISA KEVPlex Media Server External Control of File Name or Path Vulnerability
Vendor / product: Plex — Media Server
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.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Required action (CISA)
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.
Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://forums.plex.tv/t/plex-media-server/30447/711 9119a7d8-5eab-497f-8521-727c672e3725
- https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-266-... 9119a7d8-5eab-497f-8521-727c672e3725
- https://www.cve.org/CVERecord?id=CVE-2026-96656 9119a7d8-5eab-497f-8521-727c672e3725
- https://zmain.info/blog/plex2shell 9119a7d8-5eab-497f-8521-727c672e3725
- https://www.boredhackerblog.info/2026/10/plex-vulnerabilities-being-exploited-in.html 134c704f-9b21-4f2e-91b3-4a467353bcc0
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-96656 134c704f-9b21-4f2e-91b3-4a467353bcc0