How to fix CVE-2026-96652: Plex Media Server (exploited in the wild)

Plex Media Server before 1.43.3.10861 allows SSRF via '/player/timeline'. An attacker using any X-Plex-Token value can include a full URL in the 'protocol' parameter and force the Plex server to POST to the attacker's chosen destination.

• Severity: MEDIUM (CVSS 4.0 5.3, vector CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N).
• Weakness: CWE-918.
• NVD published 2026-09-23, status Analyzed.

Anyone running Plex Media Server in the version ranges below. Internet-facing instances are the priority.

• plex media server: up to (not including) 1.43.3.10861.

Version ranges come from the NVD CPE configuration. Confirm against the vendor advisory before you rely on them.

• Exploited in the wild: added to the CISA Known Exploited Vulnerabilities catalog on 2026-10-20; federal remediation due date 2026-11-03.
• Public proof-of-concept code: 6 GitHub repositories from 6 accounts, the first on 2026-10-17.

• EPSS (probability of exploitation activity in the next 30 days): 0.46%, higher than 39% of all scored CVEs (as of 2026-10-24).
• CVERadar threat level: 42/100 (see methodology).
• Likely ATT&CK techniques: T1190 Exploit Public-Facing Application (inferred); T1090 Proxy (inferred).

1. Find every instance. List where Plex Media Server runs, including test, DR and forgotten internet-facing systems, and record the installed version.
2. Upgrade to a fixed release. plex media server: 1.43.3.10861 or later. Get the build from the vendor advisory.
3. If you can't patch today, follow CISA's 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.
4. Verify the fix. Re-run the version check on every instance and confirm it reports the fixed build (1.43.3.10861 or later). Re-scan from outside if the service is exposed.
5. Hunt for signs of earlier compromise. If the system was exposed before you patched, assume it may have been hit and check the items below.
6. Rotate credentials stored on or used by the affected system if you cannot rule out compromise, and keep the logs you reviewed.

Detection hints

• T1190 Exploit Public-Facing Application: Review WAF, reverse-proxy and application logs for unusual requests to Media Server (odd paths, oversized or encoded payloads, bursts of errors), going back to at least 2026-09-23.

Detection commands are generic starting points, not CVE-specific signatures. Use the indicators from the vendor advisory when it publishes them.

• NVD: CVE-2026-96652 nvd.nist.gov/vuln/detail/CVE-2026-96652
• CVE.org record www.cve.org/CVERecord?id=CVE-2026-96652
• Vendor link from CISA KEV forums.plex.tv/t/important-security-update-for-plex-media-server-v1-43
• Release Notes forums.plex.tv/t/plex-media-server/30447/711
• CISA KEV catalog www.cisa.gov/known-exploited-vulnerabilities-catalog
• FIRST EPSS (2026-10-24) api.first.org/data/v1/epss?cve=CVE-2026-96652