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

> An admin user can write arbitrary files that execute on load due to unsafe handling of transcoder options and missing signature checks.

- **Severity:** High 8.6 (`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`)
- **Exploited in the wild:** Yes, since 20 Oct 2026 (CISA KEV)
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** GHSA-2g2v-9wf5-6m3g

## What is CVE-2026-96656?

CVE-2026-96656 is a high-severity path traversal vulnerability in Plex Media Server, published on 23 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

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.

Weakness: CWE-73 (External Control of File Name or Path)

## Which versions are affected by CVE-2026-96656?

It affects 1 product.


Products: Plex Media Server.

## How do I fix CVE-2026-96656?

No fix has been published for CVE-2026-96656 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 23 Oct 2026.

## Is CVE-2026-96656 being exploited?

Yes. Attackers have exploited CVE-2026-96656 in the wild since at least 20 Oct 2026.

Public exploit code:

- Incident write-up: unsigned .so in the Plex Media Server codec cache executes a dropper on every transcode (CVE-2026-96656) — IOCs, STIX, YARA (github_poc): https://github.com/a3igner/plex-codec-cache-implant

## Other vulnerabilities in Plex Media Server

- [CVE-2020-5741](https://insights.sbomify.com/CVE-2020-5741/): Plex Media Server Remote Code Execution (high 7.2, exploited in the wild)
- [CVE-2026-96654](https://insights.sbomify.com/CVE-2026-96654/): Plex Media Server Improper Neutralization of Encoded URI Schemes in a Web Page (medium 6.9, exploited in the wild)
- [CVE-2026-96652](https://insights.sbomify.com/CVE-2026-96652/): Plex Media Server Server-Side Request Forgery (SSRF) (medium 5.3, exploited in the wild)
- [CVE-2026-96655](https://insights.sbomify.com/CVE-2026-96655/): Plex Media Server Server-Side Request Forgery (SSRF) (medium 5.3, exploited in the wild)
- [CVE-2018-13415](https://insights.sbomify.com/CVE-2018-13415/): XML external entity in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-96656 and fix it if it is affected.

What it is: CVE-2026-96656 is a high-severity path traversal vulnerability in Plex Media Server, published on 23 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2026-96656 in the wild since at least 20 Oct 2026.

Affected product: Plex Media Server. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-96656/ (Markdown: https://insights.sbomify.com/CVE-2026-96656/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-96656
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-96656
- OSV: https://osv.dev/vulnerability/CVE-2026-96656

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-96656/
Summaries are generated and may contain mistakes; the official description above is the record.