YoutubeDLSharp allows command injection on windows system due to non sanitized arguments

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.2 · CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L

EPSS

• CVE-2025-43858: 0.26% estimated exploitation activity in the next 30 days; percentile 18.38 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary This vulnerability only apply when running on a Windows OS. An unsafe conversion of arguments allows the injection of a malicous commands when starting yt-dlp from a commands prompt. [!CAUTION] NOTE THAT DEPENDING ON THE CONTEXT AND WHERE THE LIBRARY IS USED, THIS MAY HAVE MORE SEVERE CONSEQUENCES. FOR EXAMPLE, A USER USING THE LIBRARY LOCALLY IS A LOT LESS VULNERABLE THAN AN ASP.NET APPLICATION ACCEPTING INPUTS FROM A NETWORK/INTERNET. Details The vulnerability have been implemented in a commit (https://github.com/Bluegrams/YoutubeDLSharp/commit/fdf3256da18d0e2da4a2f33ad4a1b72ff8273a50) 3 year ago to fix a issue with unicode characters on Windows. ( In the latest version at the time of writing this, the code seems to have moved here : https://github.com/Bluegrams/YoutubeDLSharp/blob/b2f7968a2ef06a9c7b2c212785cfeac0b187b6d8/YoutubeDLSharp/YoutubeDLProcess.cs#L87 ) In this commit, a new way of starting yt-dlp was implemented, method that was defined as the default behaviour.…

Published by the source

23 Apr 2025, 22:25 UTC

Last modified by the source

24 Apr 2025, 19:20 UTC

Source last checked

26 Oct 2026, 17:03 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2jh5-g5ch-43q5

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# Patch Next advisory brief: CVE-2025-43858

Advisory: YoutubeDLSharp allows command injection on windows system due to non sanitized arguments
IDs: CVE-2025-43858, GHSA-2jh5-g5ch-43q5
Record: https://patchnext.com/advisories/cve-2025-43858 (revision 1, source checked 26 Oct 2026, 17:03 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: youtubedlsharp 1.1.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet youtubedlsharp: affected >= 1.0.0-beta4, < 1.1.2; fixed in 1.1.2

## Suggested inspection (read-only)
- NuGet youtubedlsharp: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on youtubedlsharp.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2jh5-g5ch-43q5 (GitHub-reviewed advisory GHSA-2jh5-g5ch-43q5 lists affected ranges: NuGet youtubedlsharp >=1.0.0-beta4 <1.1.2)

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