Medium · CVSS 6.9CVE-2026-109966

yt-dlp-web-ui through 4.0.0 Argument Injection via Service.Formats JSON-RPC MethodCVE-2026-109966

Answer in brief

CVE-2026-109966 records a Medium severity (CVSS 6.9) vulnerability in yt-dlp-web-ui through 4.0.0 Argument Injection via Service.Formats JSON-RPC Method. The current sources do not mark it as known exploited. The current feed maps marcopiovanello/yt-dlp-web-ui (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 13, 2026Updated Oct 13, 2026Source checked Oct 13, 2026First seen by HOL Oct 13, 2026Material review Oct 13, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.9
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 6.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps marcopiovanello/yt-dlp-web-ui (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
marcopiovanello/yt-dlp-web-uigeneric	>=0 <=4.0.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for marcopiovanello/yt-dlp-web-ui.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Oct 13, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 13, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 13, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.