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

> An administrator can inject malicious HTML into Media Manager type names, leading to stored XSS and potential session theft when other administrators interact with the media.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 23 Sep 2026
- **Updated:** 23 Sep 2026
- **Also known as:** GHSA-mf2p-wjp4-99pq

## What is CVE-2026-63001?

CVE-2026-63001 is a medium-severity cross-site scripting vulnerability in redaxo core, published on 23 Sep 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-63001?

2 open source packages ship an affected version, including redaxo/source. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `redaxo/source` | Packagist | All versions | 5.21.2 |
| `redaxo/source` | Packagist | All versions | 5.21.2 |

Products: Redaxo Redaxo.

## How do I fix CVE-2026-63001?

Upgrade redaxo/source to 5.21.2 or later.

## Is CVE-2026-63001 being exploited?

There is no known exploitation of CVE-2026-63001 in the wild and no public exploit code.

## Other vulnerabilities in redaxo core

- [CVE-2018-18200](https://insights.sbomify.com/CVE-2018-18200/): SQL injection in n/a (critical 9.8)
- [CVE-2018-17831](https://insights.sbomify.com/CVE-2018-17831/): SQL injection in n/a (critical 9.8)
- [CVE-2026-21857](https://insights.sbomify.com/CVE-2026-21857/): Redaxo has Path Traversal in Backup Addon Leading to Arbitrary File Read (high 8.3)
- [CVE-2006-2843](https://insights.sbomify.com/CVE-2006-2843/): Code injection in n/a (high 7.5)
- [CVE-2006-2844](https://insights.sbomify.com/CVE-2006-2844/): Multiple PHP remote file inclusion vulnerabilities in Redaxo 3.0 allow remote attackers to execute arbitrary PHP code via a URL in the REX[I (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-63001 and fix it if it is affected.

What it is: CVE-2026-63001 is a medium-severity cross-site scripting vulnerability in redaxo core, published on 23 Sep 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-63001 in the wild and no public exploit code.

Affected packages and fixed versions:
- redaxo/source (Packagist): affected all versions; fixed in 5.21.2
- redaxo/source (Packagist): affected all versions; fixed in 5.21.2

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-63001/ (Markdown: https://insights.sbomify.com/CVE-2026-63001/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63001
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63001
- OSV: https://osv.dev/vulnerability/CVE-2026-63001

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63001/
Summaries are generated and may contain mistakes; the official description above is the record.