High severity · published Sep 23, 2026
CVE-2026-96656
Plex Media Server arbitrary file write
In wildKEV
7.2
CVSS
1.8%
EPSS
Yes
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.8% · higher than 78% of CVEs
Exploited in the wildYes
CISA KEVListed Oct 20, 2026
Federal remediation dueOct 23, 2026
Ransomware campaign useNot known
Affected products
Which versions
MS
Media Server · Plex
before 1.43.3.10861 · source: vendor, NVD, KEV
In the news
AdvisoryHigh
CISA Adds Six Known Exploited Vulnerabilities to Catalog
CISA has added six new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog , based on evidence of active exploitation. CVE-2026-96652 Plex Media Server Server-Side Request Forgery (SSRF) Vulnerability CVE-2026-96654 Plex Media Server Improper Neutralization of Encoded URI Schemes in a Web Page Vulnerability CVE-2026-96655 Plex Media Server Server-Side Request Forgery (SSRF) Vulnerability CVE-2026-96656 Plex Media Server External Control of File Name or Path Vulnerability   CVE-2026-106931 EG Secure Solutions SiteGuard Server Edition OS Command Injection Vulnerability CVE-2026-110936 Siemens Software Center Uncontrolled Search Path Element Vulnerability  These types of vulnerabilities are a frequent attack vector for malicious cyber actors and pose significant risks to the federal enterprise. Binding Operational Directive (BOD) 26-04: Prioritizing Security Updates Based on Risk establishes vulnerability management requirements for Federal Civilian Executive Branch (FCEB) agencies. BOD 26-04 reinforces the importance of the KEV Catalog and requires federal agencies to prioritize rapid remediation of high-risk vulnerabilities, specifically those identified by Common Vulnerabilities and Exposures (CVEs) listed in CISA’s KEV Catalog on publicly exposed assets that grant total control of the asset post-exploitation, while deferring action for lower-risk vulnerabilities. BOD 26-04 further establishes basic expectations fo...
Oct 20, 2026·CISA Advisories
VulnerabilityHigh
[CISA KEV] CVE-2026-96656: Plex Media Server - Plex Media Server External Control of File Name or Path Vulnerability
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.
MSMedia ServerCVE-2026-96656
Oct 20, 2026·CISA KEV