Plex Media Server Improper Neutralization of Encoded URI Schemes in a Web Page
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.
CISA deadline 2026-10-23 · due tomorrow · applies to US federal civilian agencies; used elsewhere as a reference SLA
What happened
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.
Who is affected
Plex Media Server. Affected version ranges are listed in the vendor advisory and the NVD entry linked under Sources.
Weakness class: CWE-84.
Timeline
- Added to CISA KEVExploitation in the wild confirmed by CISA
- CISA remediation deadlinedue tomorrow
Sources
- NVD entry for CVE-2026-96654 nvd.nist.gov/vuln/detail/CVE-2026-96654
- CISA Known Exploited Vulnerabilities catalog www.cisa.gov/known-exploited-vulnerabilities-catalog
- forums.plex.tv forums.plex.tv/t/important-security-update-for-plex-media-server-v1-43-2-and-earlier/942319
- cisa.gov www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- cisa.gov www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- nvd.nist.gov nvd.nist.gov/vuln/detail/CVE-2026-96654