GHSA-vx4q-3cr2-7cg2 is a high-severity (CVSS 8.3) CWE-74 vulnerability in yt-dlp. A fix is available for yt-dlp — see the affected versions and patch details below.
yt-dlp: Arbitrary code execution via manifest downloads with aria2c
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-vx4q-3cr2-7cg2.
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-vx4q-3cr2-7cg2 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 378,567 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
If aria2c is used as an external downloader for a fragmented manifest format (such as an HLS/DASH stream), yt-dlp passes insufficiently sanitized input to aria2c that allows an attacker to perform an arbitrary file write. On Windows platforms, this can lead to immediate arbitrary code execution. On non-Windows platforms, this can lead to arbitrary code execution upon the next invocation of yt-dlp.
Details
When downloading a fragmented manifest format such as an HLS or DASH stream, yt-dlp first extracts a list of all fragment URLs from the stream's manifest. If the user has selected aria2c as an external downloader, yt-dlp then constructs an input file for aria2c from the fragment URL list and passes its filepath as the argument to aria2c's -i option.
aria2c's -i (or --input-file) option allows for downloading a list of URIs from the given text file. The text file must be formatted as a list of URIs separated by newlines. aria2c's format permits configuration lines for each URI, which can contain command-line options to be given to aria2c. These optional lines follow each URI line and are signified only by leading whitespace. yt-dlp constructs the input file with these optional lines so that it's able to specify the output filename for each fragment using the out= option.
yt-dlp's utilization of the aria2c input file format presents two known attack vectors:
-
An attacker can craft a malicious DASH manifest with one or more fragment URLs that contain
, which is the HTML escape sequence for a newline. yt-dlp interprets this escape sequence as an actual newline character when writing the fragment URLs to the aria2c input file, which allows for an attacker to inject arbitrary aria2c options into the input file. With option injection, the attacker can achieve arbitrary file writes. This attack vector is possible only via downloads of DASH formats, since their manifests are an XML format which necessitates unescaping of HTML special characters. -
An attacker can craft a malicious metadata response where the data parsed by yt-dlp as the
titlefield (or any other metadata field that the user includes in their output template) contains strategically placed newlines and magnet URIs. If the user has passed the--no-windows-filenameoption to disable sanitization of newlines in output filenames, the attacker is able to achieve arbitrary file writes by injecting arbitrary URIs and options into the aria2c input file. This attack vector is possible via downloads of both HLS and DASH formats.
On Windows, attacker-controlled file writes can lead to immediate arbitrary code execution: the attacker could write a malicious executable file named ffmpeg.exe to the current working directory, and it could be invoked during the postprocessing stage if the user's yt-dlp.exe also resides in the current working directory.
On all platforms, attacker-controlled file writes can lead to arbitrary code execution on repeat invocations of yt-dlp: the attacker could write a yt-dlp configuration file (yt-dlp.conf) to the current working directory containing a malicious --exec argument.
Patches
yt-dlp version 2026.06.09 fixes this issue by removing support for downloading fragmented manifest formats with aria2c.
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:
- Add
--downloader dash,m3u8:nativeto your yt-dlp command.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | yt-dlp | all versions | 2026.6.9pip install --upgrade 'yt-dlp==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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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-vx4q-3cr2-7cg2 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-vx4q-3cr2-7cg2 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-vx4q-3cr2-7cg2. 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-vx4q-3cr2-7cg2 in your dependencies?
O3 Security finds GHSA-vx4q-3cr2-7cg2 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.