Summary
Plex Media Server contains a server-side request forgery (SSRF) vulnerability that could allow an authenticated user to request arbitrary internal or external addresses via the '/video/:/transcode/universal' path parameter. This vulnerability can be chained with CVE-2026-96652, CVE-2026-96654, and CVE-2026-96656.
What to do
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.
Notes and references
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-2026-96655