CVEs / CVE-2026-96656
CVE-2026-96656: Plex Media Server External Control of File Name or Path Vulnerability
- Known exploited in the CISA KEV catalog since 20 Oct 2026
- high 8.6 CVSS 4.0 (from the CNA)
- EPSS 1.78% chance of exploitation in the next 30 days, higher than 78% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Plex Media Server contains an external control of file name or path vulnerability which can allow an admin user to write arbitrary files that may be executed on load. This vulnerability can be chained with CVE-2026-96652, CVE-2026-96654, and CVE-2026-96655.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Plex Media Server | before 1.43.3.10861 | 1.43.3.10861 |
Exploitation
| In CISA KEV since | 20 Oct 2026 |
|---|---|
| Due date for US federal agencies | 23 Oct 2026 |
| Used in ransomware campaigns | Unknown |
| 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. |
Severity
| 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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XScored by the CNA (9119a7d8-5eab-497f-8521-727c672e3725) |
|---|---|
| Weakness | CWE-73 |
References
- CVE-2026-96656 on NVD
- CVE-2026-96656 in the CISA KEV catalog
- https://forums.plex.tv/t/important-security-update-for-plex-media-server-v1-43-2-and-earlier/942319 (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- https://forums.plex.tv/t/plex-media-server/30447/711 Release Notes
- https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-266-01.json Third Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2026-96656 Third Party Advisory, VDB Entry
- https://zmain.info/blog/plex2shell Third Party Advisory
- https://www.boredhackerblog.info/2026/10/plex-vulnerabilities-being-exploited-in.html Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-96656 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.