Summary
Plex Media Server contains an improper neutralization of encoded URI schemes in a web page vulnerability that could allow an attacker to call other plugins' functions and supply their own parameters. This vulnerability can be chained with CVE-2026-96652, CVE-2026-96655, and CVE-2026-96656.
Remediation
CISA required actionApply 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.
References
- Advisoryhttps://forums.plex.tv/t/important-security-update-for-plex-media-server-v1-43-2-and-earlier/942319
- Advisoryhttps://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- Advisoryhttps://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- Advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-96654
- Advisoryhttps://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-266-01.json
- Advisoryhttps://zmain.info/blog/plex2shell
- Referencehttps://www.cve.org/CVERecord?id=CVE-2026-96654
- Referencehttps://forums.plex.tv/t/plex-media-server/30447/711
- Referencehttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-96654