CVE-2026-96656
Plex Media Server External Control of File Name or Path Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 23 October 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 4.0
- 8.6 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/M
- EPSS
- 1.79% probability · 78th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 20 October 2026 · due 23 October 2026
- Weakness
- CWE-73
- Affected
- plex/media server
- Source
- 9119a7d8-5eab-497f-8521-727c672e3725
EPSS moved from 0.3% on 24 September 2026 to 1.8% on 29 October 2026.
CISA notes
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. https://forums.plex.tv/t/important-security-update-for-plex-media-server-v1-43-2-and-earlier/942319 ; ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-96656
References
- https://forums.plex.tv/t/plex-media-server/30447/711Release Notes
- https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-266-01.jsonThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2026-96656Third Party Advisory, VDB Entry
- https://zmain.info/blog/plex2shellThird Party Advisory
- https://www.boredhackerblog.info/2026/10/plex-vulnerabilities-being-exploited-in.htmlThird Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-96656US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.