# CVE-2026-49247: Jellyfin: Potential Authenticated path traversal in /ClientLog/Document

> Authenticated users can exploit path traversal in the ClientLog endpoint to write arbitrary files to the server filesystem.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Jun 2026
- **Updated:** 26 Jun 2026
- **Also known as:** GHSA-jg92-mrxq-vv75

## What is CVE-2026-49247?

CVE-2026-49247 is a high-severity path traversal vulnerability in jellyfin, published on 24 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Jellyfin is an open source self hosted media server. From 10.9.0 until 10.11.10, the POST /ClientLog/Document endpoint accepts the Authorization header's Client and Version fields and uses them unsanitized as components of the on-disk filename when persisting client-uploaded log documents. As a result, any authenticated non-admin user can include ../ sequences in the Client field to cause Jellyfin to write attacker-controlled content to arbitrary paths reachable by the Jellyfin service user, with a forced .log suffix. This vulnerability is fixed in 10.11.10.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-49247?


## How do I fix CVE-2026-49247?

No fix has been published for CVE-2026-49247 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-49247 being exploited?

There is no known exploitation of CVE-2026-49247 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-49247 and fix it if it is affected.

What it is: CVE-2026-49247 is a high-severity path traversal vulnerability in jellyfin, published on 24 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-49247 in the wild and no public exploit code.

Affected product: jellyfin. 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-2026-49247/ (Markdown: https://insights.sbomify.com/CVE-2026-49247/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-49247
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-49247
- OSV: https://osv.dev/vulnerability/CVE-2026-49247

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-49247/
Summaries are generated and may contain mistakes; the official description above is the record.