---
id: CVE-2026-109966
title: >-
  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
summary: >-
  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 c…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-88
published: '2026-10-13'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T14:17:36.217'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-109966'
references:
  - url: 'https://github.com/marcopiovanello/yt-dlp-web-ui'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/marcopiovanello/yt-dlp-web-ui/blob/v4.0.0/server/formats/parser.go
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/vazzzy071-crypto/security-advisories/blob/main/advisories/2026-10-marcopiovanello-yt-dlp-web-ui-rpc-arg-injection.md
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/yt-dlp-web-ui-through-4.0.0-argument-injection-via-service-formats-json-rpc-method
    label: disclosure@vulncheck.com
tags:
  - nvd
ingestedAt: '2026-10-13T14:29:01.858Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.