CVE-2026-96656
HIGH 8.6 KNOWN EXPLOITED PoC CATALOGUEDPlex 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.
Confirmed exploited in the wild — in CISA KEV since 2026-10-20. Patch or mitigate now.
Exploitation likelihood
1.8%chance of exploitation in 30 days · 78th percentile
Impact if exploited
8.6CVSS 4.0 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires an admin / high-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
Public PoC or exploit resources are catalogued below.
- VulnCheck KEV · XDB 81db309969f5 · Linked repository
- VulnCheck KEV · XDB 88e7f1215926 · Linked repository
Listed by the named source; Vulnpedia has not tested these resources.
PoC data: JSON
Resource commands
curl -s https://vulnpedia.com/cve/CVE-2026-96656/poc.jsonMachine-readable PoC index for this CVE (for automation).Search for new PoCs
Search GitHub now — results may be empty or unverified.
Tracked sources are checked daily for recent CVEs, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Data snapshot:
Weakness (CWE)
- CWE-73: External Control of File Name or Path
CVSS vector
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
References and research data (JSON)
Unverified PoC candidates
Catalogue matches for further research. These repositories have not been validated as working exploits.
1 candidate
- https://github.com/a3igner/plex-codec-cache-implant
Incident write-up: unsigned .so in the Plex Media Server codec cache executes a dropper on every transcode (CVE-2026-96656) — IOCs, STIX, YARA
PoC-in-GitHub · CVE-2026-96656
PoC-in-GitHub · CVE-2026-96656 · Updated 2026-10-18T10:12:10Z
Additional exploitation reports
Source-specific reports, separate from CISA KEV. Repeated observations from one source are not independent confirmations.
- VulnCheck KEV · 2026-10-18T00:00:00Z
Source 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.
Source ransomware assessment: Unknown
VulnCheck KEV · CVE-2026-96656 · Updated 2026-10-18T00:00:00Z - VulnCheck KEV · 2026-10-18T00:00:00ZVulnCheck KEV · CVE-2026-96656
- VulnCheck KEV · 2026-10-20T00:00:00ZVulnCheck KEV · CVE-2026-96656
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Plex | Media Server | < 1.43.3.10861 |
All CVSS metrics
- HIGH 8.6 v4.0 · CNA Primary
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 - HIGH 7.2 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - HIGH 8.6 v4.0 · NVD Secondary
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - HIGH 7.2 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
References
Patches & mitigations
- https://forums.plex.tv/t/plex-media-server/30447/711 CVE record · cisa-cg · Updated 2026-09-23T16:07:10.048Z
NVD · CVE-2026-96656 · Updated 2026-10-21T13:09:18.913
Advisories
- https://www.cve.org/CVERecord?id=CVE-2026-96656 CVE record · cisa-cg · Updated 2026-09-23T16:07:10.048Z
NVD · CVE-2026-96656 · Updated 2026-10-21T13:09:18.913 - https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-266-01.json CVE record · cisa-cg · Updated 2026-09-23T16:07:10.048Z
NVD · CVE-2026-96656 · Updated 2026-10-21T13:09:18.913 - https://zmain.info/blog/plex2shell CVE record · cisa-cg · Updated 2026-09-23T16:07:10.048Z
NVD · CVE-2026-96656 · Updated 2026-10-21T13:09:18.913 - https://www.boredhackerblog.info/2026/10/plex-vulnerabilities-being-exploited-in.html CVE record · CISA-ADP · Updated 2026-10-21T03:56:10.489Z
NVD · CVE-2026-96656 · Updated 2026-10-21T13:09:18.913
VulnCheck KEV · CVE-2026-96656 · Updated 2026-10-18T00:00:00Z - https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-96656 CVE record · CISA-ADP · Updated 2026-10-21T03:56:10.489Z
NVD · CVE-2026-96656 · Updated 2026-10-21T13:09:18.913 - https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-85370 EUVD · EUVD-2026-85370
- https://vulncheck.com/kev VulnCheck KEV · CVE-2026-96656 · Updated 2026-10-18T00:00:00Z
Technical & other
- https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json VulnCheck KEV · CVE-2026-96656 · Updated 2026-10-18T00:00:00Z
- https://vulncheck.com/xdb/81db309969f5 VulnCheck KEV · 81db309969f5 · Updated 2026-10-18T00:00:00Z
- https://github.com/gmh5225/plex2shell VulnCheck KEV · 81db309969f5 · Updated 2026-10-18T00:00:00Z
- https://vulncheck.com/xdb/88e7f1215926 VulnCheck KEV · 88e7f1215926 · Updated 2026-10-18T00:00:00Z
- https://github.com/code-zm/plex2shell VulnCheck KEV · 88e7f1215926 · Updated 2026-10-18T00:00:00Z