Vulnerability · CVE-2026-96656
plex media_server External Control of File Name or Path
Published Sep 23, 2026 · catalog updated Oct 21, 2026 · Plex Media Server
Patch now
CVE-2026-96656 is in the CISA known-exploited catalog, due Oct 23, 2026. Confirm Plex Media Server against the vendor advisory and apply that fix. The CVSS score does not change the priority.
- Severity
- High8.6
- Known exploitation
- CISA KEV and VulnCheck KEV
- EPSS
- 0.82%
- Remediation
- Remediation guidance
- Affected products
- cpe plex/media server · vendor Plex · vendor Plex Media Server · vendor Plex media_server · vendor plex media_server
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. Initial-access exploit intelligence.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe plex/media server< 1.43.0.10861
- cpe plex/media server< 1.43.3.10861
- vendor Plexversion unspecified
- vendor Plex Media Serverversion unspecified
- vendor Plex media_serverversion unspecified
- vendor plex media_serverversion unspecified
How to fix CVE-2026-96656
Recommended remediation
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. CISA due date Oct 23, 2026.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
CVE-2026-96656 is in the CISA known-exploited catalog, due Oct 23, 2026. Confirm Plex Media Server against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Which versions are affected?
Compare what you have installed with plex/media server < 1.43.0.10861; plex/media server < 1.43.3.10861. 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.
What should an analyst verify?
CWE-73. EPSS 0.82%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Oct 18, 2026 · VulnCheck KEV
Detected
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.
Oct 18, 2026 · CISA KEV
Known exploited
Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Oct 20, 2026 · NIST NVD
Updated
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.
Oct 20, 2026 · NIST NVD
Updated
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.
Oct 21, 2026 · NIST NVD
Updated
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.
Oct 21, 2026 · NIST NVD
Updated
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.
Oct 23, 2026 · CISA KEV
Remediation due
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
Sources
- CISA KEVConfirmed exploitationCVE-2026-96656
Plex Media Server contains an external control of file name or path vulnerability which can allow an admin user to write arbitrary files that may be executed on load. This vulnerability can be chained with CVE-2026-96652, CVE-2026-96654, and CVE-2026-96655.
cisa.gov - CVE.orgVulnerability recordCVE-2026-96656
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-96656
30-day exploitation probability 0.82%
first.org - EUVDVulnerability recordEUVD-2026-85370
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
euvd.enisa.europa.eu - NIST NVDVulnerability recordCVE-2026-96656
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
nvd.nist.gov - VulnCheck KEVConfirmed exploitationCVE-2026-96656
Plex Media Server contains an external control of file name or path vulnerability which can allow an admin user to write arbitrary files that may be executed on load. This vulnerability can be chained with CVE-2026-96652, CVE-2026-96654, and CVE-2026-96655.
vulncheck.com
References
- EUVD record · euvd.enisa.europa.eu
- CISA note · forums.plex.tv
- Release Notes · forums.plex.tv
- CISA note · nvd.nist.gov
- Third Party Advisory · raw.githubusercontent.com
- VulnCheck exploitation evidence · boredhackerblog.info
- Reference · cisa.gov
- CISA note · cisa.gov
- CISA note · cisa.gov
- VulnCheck exploitation evidence · cisa.gov
- Third Party Advisory · cve.org
- Third Party Advisory · zmain.info
Freshness
Last verified in this catalog Oct 23, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.