CVE-2026-96656: Plex Media Server External Control of File Name or Path Vulnerability

Q: How do I fix CVE-2026-96656?

media server: upgrade to 1.43.3.10861. Exact commands for each OS are on this page.

Q: Is CVE-2026-96656 being exploited?

Yes. CVE-2026-96656 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

Q: What does CVE-2026-96656 affect?

CVE-2026-96656 affects media server. Severity is high (CVSS 7.2). 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 file

Q: How urgent is CVE-2026-96656?

Priority 64/100. High severity; Exploited in the wild (CISA KEV)

Patch now

HIGH 7.2EXPLOITEDUPGRADE

CVE-2026-96656 is a high-severity flaw (CVSS 7.2) affecting media server, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity
Exploited in the wild (CISA KEV)

A fixed release or distro patch exists.

Risk facts

CVSS score	7.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	0.8% (top 43%)
CISA exploited list	Yes, fix due 2026-10-23
Weakness	CWE-73
Published	2026-09-23
Last modified	2026-10-21

Publisher (CNA): Cybersecurity and Infrastructure Security Agency (CISA) U.S. Civilian Government · Vendor: plex

Last updated 2026-10-21 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-23 17:17 UTCPublished CVE record published
2026-10-20Exploited Added to the CISA Known Exploited Vulnerabilities list
2026-10-21 13:09 UTCUpdated Record last modified
2026-10-23Deadline CISA due date for US federal agencies to patch

plex media server UPGRADE

Affected: < 1.43.3.10861

Fixed in: 1.43.3.10861

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy media-server || rpm -q media-server || media-server --version

2. UPGRADE to 1.43.3.10861 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade media-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade media-server

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Fedora 46 · retext · FIXED · 8.1.0-1.fc46 · FEDORA-2026-0602a84203 · source

sudo dnf upgrade --advisory=FEDORA-2026-0602a84203

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: a3igner/plex-codec-cache-implant (0 stars)

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-96656?

media server: upgrade to 1.43.3.10861. Exact commands for each OS are on this page.

Is CVE-2026-96656 being exploited?

Yes. CVE-2026-96656 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2026-96656 affect?

CVE-2026-96656 affects media server. Severity is high (CVSS 7.2). 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 file

How urgent is CVE-2026-96656?

Priority 64/100. High severity; Exploited in the wild (CISA KEV)

Related CVEs

CVE-2026-96652 MEDIUM 4.3 EXPLOITED UPGRADE Plex Media Server Server-Side Request Forgery (SSRF) Vulnerability
CVE-2026-96654 MEDIUM 6.5 EXPLOITED UPGRADE Plex Media Server Improper Neutralization of Encoded URI Schemes in a Web Page Vulnerability
CVE-2026-96655 MEDIUM 4.3 EXPLOITED UPGRADE Plex Media Server Server-Side Request Forgery (SSRF) Vulnerability

References

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