Plex Media Server Server-Side Request Forgery (SSRF) Vulnerability

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.

CheckOps priority index

3.4/10 Patch within 7 days

Severity5.3

Probability0.2

Exploitation2/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 1.6% higher than 76.3% of CVEs

CVSS 4.0 5.3 AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/

Exploited for 14 days 20 Oct 2026

CISA due date 03 Nov 2026 for US federal agencies

Exploitation probability EPSS · FIRST

EPSS probability (%)Percentile among all CVEs

Exploitation signals 2 / 5

KEV catalog (CISA)20 Oct 2026
Exploited in EUVD (ENISA)20 Oct 2026
Used by ransomwareno
EPSS above 10 %1.6%
No account, over the networkno

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: 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.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Affected products

Media Server

Affected versions

0 <1.43.3.10861

Weaknesses (CWE)

CWE-918

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

23 Sept 2026
Published
20 Oct 2026
Exploitation reported (ENISA)
20 Oct 2026
Added to the KEV catalog
03 Nov 2026
CISA remediation due date

References

Other exploited vulnerabilities from the same vendor

CVE-2026-96656Plex Media Server External Control of File Name or Path Vulnerability
4.7 · Rising fast
CVE-2026-96654Plex Media Server Improper Neutralization of Encoded URI Schemes in a Web Page Vulnerability
4.6 · Rising fast
CVE-2026-96652Plex Media Server Server-Side Request Forgery (SSRF) Vulnerability
3.4 · Rising fast
CVE-2020-5741Plex Media Server Remote Code Execution Vulnerability
6.9 · Background exploitation