CVE-2026-96656: Plex Media Server External Control of File Name or Path Vulnerability
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
Plex Media Server before 1.43.3.10861 allows an admin user to write arbitrary files that may be executed on load. The preference TranscoderH264Options is appended verbatim to x264’s option string on every transcode. At startup, all .so files are run without signature, execute bit, or symbol checks.
Description quoted from the CVE record (assigned by cisa-cg, published 2026-09-23).
Weakness: CWE-73 External Control of File Name or Path
How it can be exploited
Exploitable over the network with low attack complexity with no special attack requirements needing high privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: no. Technical impact: total.
- On CISA KEV since
- 2026-10-20
- US federal deadline
- 2026-10-23
- Ransomware use
- Not known
Public exploit evidence (Exploit Observer)
Also known as: EUVD-2026-85370, GHSA-2g2v-9wf5-6m3g
VEDAS cluster: VEDAS:BARNBARRACUDA
Exploit Observer links 3 pieces of public exploit code or detection modules that name this CVE or one of its aliases.
Exploit code and modules (3)
Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.
- Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2026/CVE-2026-96656.rules
- Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2026/CVE-2026-96656.rules
- Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2026/CVE-2026-96656.rules
Vulnerability databases and vendor advisories (4)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-85370
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-2g2v-9wf5-6m3g
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-96656
- Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-96656
69 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.018
some chance of attack soon - VEDAS
- 0.985
strong exploit evidence - On CISA KEV
- Yes, since 2026-10-20
- Detection rule
- Suricata
Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish. The vertical line is the day CISA added it to its exploited list.
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| Plex Media Server | before 1.43.3.10861 | 1.43.3.10861 is not affected |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
Exploit Observer also maps it to: plex media_server.
How to fix it
Fixed versions stated in the CVE record: 1.43.3.10861.
CISA 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.
Vendor guidance:
- url (release-notes)
How to detect it
Suricata rules (network detection)
1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-96656 Plex Media Server - Arbitrary File Write via TranscoderH264Options Preference. Add them to your Suricata rule set and reload.
Show the rules
alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-96656 Plex Media Server - Arbitrary File Write via TranscoderH264Options Preference"; flow:established,to_server; http.method; content:"PUT"; http.uri; content:"/:/prefs"; nocase; fast_pattern; content:"TranscoderH264Options="; nocase; classtype:web-application-attack; reference:cve,CVE-2026-96656; reference:url,https://www.exploit.observer/?keyword=CVE-2026-96656&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=plex&match=exact; sid:1099800; rev:1;)
CVE-2026-96656.rules on GitHub
Advisories on this CVE
- Plex2Shell, Plex Media Server four-CVE chain (CVE-2026-96652 / -96654 / -96655 / -96656) (20 Oct 2026)
References
Vendor advisories and patches
- url (release-notes)
Exploits and technical analysis
- url (third-party-advisory)
- url (third-party-advisory)
- https://www.boredhackerblog.info/2026/10/plex-vulnerabilities-being-exploited-in.html (third-party-advisory)
Government sources
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-96656 (government-resource)
Other references
- url (vdb-entry)
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.