Skip to content

yt-dlp: File Downloader cookie leak with curl

Moderate severity GitHub Reviewed Published Jun 9, 2026 in yt-dlp/yt-dlp • Updated Jun 16, 2026

Package

pip yt-dlp (pip)

Affected versions

>= 2023.9.24, < 2026.6.9

Patched versions

2026.6.9

Description

Summary

If curl is used an external downloader for yt-dlp, cookies may be leaked to an unintended host upon HTTP redirect or when the host for download fragments differs from their parent manifest's.

This is the equivalent to GHSA-v8mc-9377-rwjj for the curl downloader. The vulnerable behavior is present in yt-dlp released since 2023.09.24.

Details

At the file download stage, the cookies are passed by yt-dlp to the file downloader via --cookie. However, unless these are loaded from a file, this operation does not activate the cookie engine. As a result, curl will send cookies with requests to domains or paths for which the cookies are not scoped.

An example of a potential attack scenario exploiting this vulnerability:

  1. an attacker has crafted a malicious website with an embedded URL designed to be detected by yt-dlp as a video download. This embedded URL has the domain of a trusted site that the user has loaded cookies for, and conducts an unvalidated redirect to a target URL.
  2. yt-dlp extracts this URL and calculates the cookies which are then passed to curl.
  3. the download URL redirects to a server controlled by the attacker, to which curl forwards the user's sensitive cookie information.

Patches

yt-dlp version 2026.06.09 fixes this issue by doing the following:

  • Pass the cookies through stdin via --cookie - if curl is version 7.59 or higher.
  • Pass the cookies via --cookie /dev/fd/0 if the system supports this device file.
  • In all other cases create a temporary file, save the cookies and then pass via --cookie <file>.

Workarounds

It is recommended to upgrade yt-dlp to version 2026.06.09 as soon as possible.

For users who are not able to upgrade:

  • Do not use --downloader curl.

References

@Grub4K Grub4K published to yt-dlp/yt-dlp Jun 9, 2026
Published to the GitHub Advisory Database Jun 16, 2026
Reviewed Jun 16, 2026
Last updated Jun 16, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(18th percentile)

Weaknesses

Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Learn more on MITRE.

CVE ID

CVE-2026-50019

GHSA ID

GHSA-f7j3-774f-rfhj

Source code

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.