CVE-2026-109966 yt-dlp-web-ui through 4.0.0 Argument Injection via Service.Formats JSON-RPC Method
Unauthenticated attackers can inject yt-dlp options to read arbitrary server files or potentially execute code via the JSON-RPC interface.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-109966?
CVE-2026-109966 is a medium-severity command injection vulnerability in marcopiovanello yt-dlp-web-ui, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
yt-dlp-web-ui through 4.0.0 contains an argument injection vulnerability that allows unauthenticated remote attackers to inject yt-dlp options by supplying a dash-prefixed url parameter to the Service.Formats JSON-RPC method. Attackers can send values like --load-info-json via /rpc/http or /rpc/ws to make yt-dlp load attacker-chosen JSON files from the server filesystem, with contents reflected in responses.
Weakness: CWE-88
Which versions are affected by CVE-2026-109966?
How do I fix CVE-2026-109966?
No fix has been published for CVE-2026-109966 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-109966 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-109966 exists.
Sources
Also known as GHSA-g8v9-4g6m-3vc9.