Plex Media Server Server-Side Request Forgery (SSRF) Vulnerability
Plex — Media Server
- Added to KEV catalog
- 20 October 2026
- Federal remediation due date
- 3 November 2026
- Weakness classification (CWE)
- CWE-918
AI Breakdown
What it is
Plex Media Server versions prior to 1.43.3.10861 contain a server-side request forgery vulnerability in the video transcoding path parameter. An authenticated attacker can exploit this weakness to force the server to make unauthorized requests to internal or external network addresses. Additionally, this flaw can be chained with vulnerabilities CVE-2026-96652, CVE-2026-96654, and CVE-2026-96656 to facilitate broader attacks.
Why it matters
This vulnerability is listed on CISA's Known Exploited Vulnerabilities catalog due to confirmed exploitation in the wild, demanding urgent attention. Although specific use in ransomware campaigns is currently unknown, attackers can leverage this access to reach sensitive internal resources that are not directly exposed to the internet. Leaving vulnerable instances unpatched exposes internal systems and networks to pivoting and exploitation.
Recommended action
Apply vendor mitigations and update Plex Media Server installations to version 1.43.3.10861 or higher in accordance with vendor guidance. IT teams should evaluate asset internet exposure and perform forensics triage and patching consistent with CISA BOD 26-04 requirements. If official mitigations cannot be applied, discontinue using the product and isolate affected assets from the network.
AI-generated from CISA and NVD data — treat as a starting point, not a substitute for your own risk assessment.
CISA Description
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.
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.
Notes
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
NVD Technical Description
Plex Media Server before 1.43.3.10861 allows an authenticated user to request arbitrary internal or external addresses via the '/video/:/transcode/universal' path parameter.
More Plex Vulnerabilities
Plex Media Server Server-Side Request Forgery (SSRF) Vulnerability
Plex Media Server External Control of File Name or Path Vulnerability
Plex Media Server Improper Neutralization of Encoded URI Schemes in a Web Page Vulnerability
Plex Media Server Remote Code Execution Vulnerability
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