---
id: "CVE-2026-96656"
kind: "vulnerability"
aliases: ["CVE-2026-96656"]
title: "Plex Media Server before 1.43.3.10861 allows an admin user to write arbitrary files that may be executed on load"
severity: "high"
cvss: 8.6
epss: null
exploited: true
status: "open"
category: "vendor"
products: [{"name": "Plex Media Server", "fixed": ["1.43.3.10861"], "affected": "< 1.43.3.10861", "ecosystem": "vendor"}, {"name": "Plex Media Server", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["docker", "exploited", "nas", "plex-media-server", "rce-chain", "self-hosted", "vendor"]
not_affected_if: ["managed-hosting"]
published_at: "2026-09-23T17:17:23+00:00"
first_seen_at: "2026-10-23T19:11:50+00:00"
updated_at: "2026-10-24T00:09:50+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-96656", "first_seen_at": "2026-10-23T19:11:50+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-23T22:43:00+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-96656", "first_seen_at": "2026-10-23T23:44:52+00:00"}]
---

# Plex Media Server before 1.43.3.10861 allows an admin user to write arbitrary files that may be executed on load

An admin user of Plex Media Server can set the TranscoderH264Options preference, which is appended verbatim to x264's options on every transcode, to write arbitrary files. At startup all .so files in the Codecs folder are loaded without signature, execute-bit or symbol checks, so a written file runs as code. CISA lists it as exploited, chained with CVE-2026-96652, -96654 and -96655.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Plex Media Server affected < 1.43.3.10861 fixed 1.43.3.10861
- vendor:Plex Media Server affected ? fixed ?

## How to check

In Plex Web: Settings > General, read the server version; anything below 1.43.3.10861 is affected (compare all four numbers). Also look in the Plex Codecs folder for .so/.dll files you did not put there.

## Fix

Update Plex Media Server to 1.43.3.10861 or later. On a NAS, download the package from Plex's Downloads page if the package manager is behind. Turn off Remote Access if not needed and do not forward port 32400 directly.

## Timeline

- 2026-10-23T19:11:50+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-96656
- 2026-10-23T22:43:00+00:00 analyst — CVE record + Plex forum notice: affected < 1.43.3.10861, fixed 1.43.3.10861. Exploited per CISA KEV (Plex2Shell chain). Did not read PoC or social posts; PoC link not saved. Check Point's 1.43.0.10861 looks like a typo.
- 2026-10-23T23:44:52+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-96656

## Documents

- [advisory] CVE Record CVE-2026-96656 https://www.cve.org/CVERecord?id=CVE-2026-96656
- [advisory] CISA adds six KEVs (Oct 20, 2026) https://www.cisa.gov/news-events/alerts/2026/10/20/cisa-adds-six-known-exploited-vulnerabilities-catalog
- [describes] Brandefense: Plex Media Server arbitrary file write (CVE-2026-96656) https://brandefense.io/knowledge-hub/vulnerabilities/cve-2026-96656/
- [discussion] Operator reports NAS compromised by Plex2Shell https://x.com/_master117/status/2113722829476626681
- [fix] Plex: Important Security Update for Plex Media Server v1.43.2 and earlier https://forums.plex.tv/t/important-security-update-for-plex-media-server-v1-43-2-and-earlier/942319
- [mentions] CISA: Hackers chain Plex flaws in Plex2Shell attacks to breach servers https://www.bleepingcomputer.com/news/security/cisa-hackers-chain-plex-flaws-in-plex2shell-attacks-to-breach-servers/
- [poc] Plex2Shell write-up (Zach Main) https://zmain.info/blog/plex2shell
- [poc] code-zm/plex2shell exploit code https://github.com/code-zm/plex2shell

## From the sources

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 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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_