CVE-2026-96656: Plex Media Server External Control of File Name or Path Vulnerability

CISA Known Exploited Vulnerabilities

Name

Plex Media Server External Control of File Name or Path Vulnerability

Vendor

Plex

Product

Media Server

Added to the catalog

2026-10-20

Due date for US federal agencies

2026-10-23

Weaknesses

CWE-73

Catalog version

2026.10.30

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 (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.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

• https://forums.plex.tv/t/important-security-update-for-plex-media-server-v1-43-2-and-earlier/942319
• https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
• 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

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status

Analyzed

Published

2026-09-23T17:17:23.840

Last modified

2026-10-21T13:09:18.913

Weaknesses

CWE-73

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.

References

• 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)

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:42:31.494Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-96656

CVE record

Title (CNA)

Plex Media Server arbitrary file write

Assigner

cisa-cg

State

PUBLISHED

Published

2026-09-23T16:07:10.048Z

Updated

2026-10-21T03:56:10.489Z

Problem types

CWE-73 External Control of File Name or Path

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.

References

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Read on 2026-11-03T02:21:47.170Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/96xxx/CVE-2026-96656.json

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

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