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Fencer Intel
critical 9.2

CVE-2025-43858 json

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

published last yr. modified last mo. also GHSA-2jh5-g5ch-43q5 , EUVD-2025-11986

cvss
9.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits
0
none known

Summary

YoutubeDLSharp is a wrapper for the command-line video downloaders youtube-dl and yt-dlp. In versions starting from 1.0.0-beta4 and prior to 1.1.2, an unsafe conversion of arguments allows the injection of a malicious commands when starting `yt-dlp` from a commands prompt running on Windows OS with the `UseWindowsEncodingWorkaround` value defined to true (default behavior). If a user is using built-in methods from the YoutubeDL.cs file, the value is true by default and a user cannot disable it from these methods. This issue has been patched in version 1.1.2.

Patch / fix

  • nuget YoutubeDLSharp 1.1.2

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
last yr.

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/Bluegrams/YoutubeDLSharp/security/advisories/GHSA-2jh5-g5ch-43q5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 9.2 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L
GitHub 3.1 9.2 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L

Affected packages

ecosystem package affected fixed in
nuget YoutubeDLSharp
>=1.0.0-beta4, <1.1.2
1.1.2

Affected products

  • Bluegrams YoutubeDLSharp

Classification

Weakness
  • CWE-77 Improper Neutralization of Special Elements used in a Command
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.