CVE-2026-96656
KEV: known exploited SSVC: activePlex Media Server arbitrary file write
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CVSS: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:X
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Attack conditions and impact
Derived from the CNA (via NVD) CVSS 3.1 vector| Metric | Value | Meaning |
|---|---|---|
| Attack vector AV | N | Network |
| Attack complexity AC | L | Low (easy) |
| Privileges required PR | H | Administrator |
| User interaction UI | N | None |
| Scope S | U | Unchanged |
| Confidentiality C | H | High |
| Integrity I | H | High |
| Availability A | H | High |
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
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.
CISA KEV entry
Plex Media Server External Control of File Name or Path Vulnerability — Plex / Media Server
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.
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.
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
CVSS assessments
| Provider | Version | Score | Vector |
|---|---|---|---|
| NVD / 9119a7d8-5eab-497f-8521-727c672e3725 (Secondary) | 4.0 | 8.6 HIGH | CVSS: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:X |
| NVD / 9119a7d8-5eab-497f-8521-727c672e3725 (Secondary) | 3.1 | 7.2 HIGH | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
| CNA / cisa-cg | 4.0 | 8.6 HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CNA / cisa-cg | 3.1 | 7.2 HIGH | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
Affected products and packages
CNA (CVE.org)
| Vendor | Product | Versions |
|---|---|---|
| Plex | Media Server | affected: 0 … < 1.43.3.10861 unaffected: 1.43.3.10861 default: unknown |
NVD CPE (1)
Show CPE list
| Vendor | Product | Range | CPE |
|---|---|---|---|
| plex | media_server | < 1.43.3.10861 | cpe:2.3:a:plex:media_server:*:*:*:*:*:*:*:* |
Linux distribution status
References (6)
- https://forums.plex.tv/t/plex-media-server/30447/711 NVD, CNA Release Notesrelease-notes
- https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-266-01.json NVD, CNA Third Party Advisorythird-party-advisory
- https://www.boredhackerblog.info/2026/10/plex-vulnerabilities-being-exploited-in.html NVD, ADP CISA-ADP Third Party Advisorythird-party-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-96656 NVD, ADP CISA-ADP US Government Resourcegovernment-resource
- https://www.cve.org/CVERecord?id=CVE-2026-96656 NVD, CNA Third Party AdvisoryVDB Entryvdb-entry
- https://zmain.info/blog/plex2shell NVD, CNA Third Party Advisorythird-party-advisory