# yt-dlp: Downstream command injection via improper sanitization of yt-dlp --write-link output

Advisory record · `GHSA-6v4j-43gg-vj32`

- **Identifiers:** `GHSA-6v4j-43gg-vj32` · `CVE-2026-55404` · `PYSEC-2026-3622`
- **State:** Confirmed
- **Severity:** CVSS 7.5 High
- **Critical:** No
- **Weakness (CWE):** [CWE-74](https://cwe.mitre.org/data/definitions/74.html)
- **Tags:** [Other injection](https://agentprime.io/advisories/tag/injection.md)
- **Published:** 24 Jul 2026
- **Updated:** 4 Aug 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 24 Jul 2026, 20:35 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `yt-dlp` (PyPI): affected `<2026.7.4`; fixed in `2026.7.4`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> The yt-dlp package versions before 2026.7.4 are vulnerable when the --write-link, --write-url-link or --write-desktop-link options are used, because the shortcut files they write (.url and .desktop) are not properly sanitized. A remote attacker who supplies crafted metadata can cause a malicious file:// target or injected shell command to be written into these files, which can run code if a user opens the generated shortcut. Upgrade yt-dlp to 2026.7.4 or later. Users who cannot upgrade should avoid those three options.

Written 5 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 7.5 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0064, the 51st percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:40 UTC: First seen by agentprime
- 31 Oct 2026, 14:40 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-6v4j-43gg-vj32)

## Sources

- [GitHub Advisory Database: GHSA-6v4j-43gg-vj32](https://github.com/advisories/GHSA-6v4j-43gg-vj32)
- [OSV: GHSA-6v4j-43gg-vj32](https://osv.dev/vulnerability/GHSA-6v4j-43gg-vj32)
- <https://github.com/yt-dlp/yt-dlp/security/advisories/GHSA-6v4j-43gg-vj32>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-55404>
- <https://github.com/yt-dlp/yt-dlp/commit/6fc85f617a5850307fd5b258477070e6ee177796>
- <https://github.com/yt-dlp/yt-dlp/commit/b6590aaa1e3808155d69c9a79a797ae484163789>
- <https://github.com/yt-dlp/yt-dlp>
- <https://github.com/yt-dlp/yt-dlp-nightly-builds/releases/tag/2026.07.04.221833>
- <https://github.com/yt-dlp/yt-dlp/releases/tag/2026.07.04>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-6v4j-43gg-vj32>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-6v4j-43gg-vj32/>. Everything for agents: <https://agentprime.io/llms.txt>.