YoutubeDLSharp: Improper Neutralization of Special Elements used in a Command
CVE-2025-43858 is a critical-severity improper neutralization of special elements used in a command vulnerability in YoutubeDLSharp from Bluegrams, with a CVSS 3.1 base score of 9.2 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. Affected YoutubeDLSharp versions: >= 1.0.0-beta4, < 1.1.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.26% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of YoutubeDLSharp you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Bluegrams | YoutubeDLSharp | >= 1.0.0-beta4, < 1.1.2 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L. Scored by CNA (github.com).
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in a Command
The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- If possible, ensure that all external commands called from the program are statically created.
- Run time: Run time policy enforcement may be used in an allowlist fashion to prevent use of any non-sanctioned commands.
More Improper Neutralization of Special Elements used in a Command vulnerabilities (CWE-77)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Improper Neutralization of Special Elements used in a Command vulnerabilities
- 7.3 High severity
- 9.8 Critical severity
- 7.2 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.3 High severity
Spotted an error? Tell us.