# CVE-2026-63002: REDAXO: Stored XSS in Mediapool Sync Page via Unescaped Filesystem Filenames

> An attacker can execute arbitrary scripts in a backend user's browser by placing malicious filenames in the media directory, leading to session theft.

- **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:** 24 Sep 2026
- **Also known as:** GHSA-w998-qmw9-mf4m

## What is CVE-2026-63002?

CVE-2026-63002 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, redaxo/src/addons/mediapool/pages/sync.php inserts filenames held in $diffFiles from the media filesystem into the Mediapool Sync page without rex_escape(). An attacker who can place an unregistered file with HTML metacharacters in the media directory can execute script in the browser of a backend user with media[sync] permission when that user opens the Sync page, 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-2026-63002?

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-2026-63002?

Upgrade redaxo/source to 5.21.2 or later.

## Is CVE-2026-63002 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-63002 exists.

## 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-2026-63002 and fix it if it is affected.

What it is: CVE-2026-63002 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-63002 exists.

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-2026-63002/ (Markdown: https://insights.sbomify.com/CVE-2026-63002/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63002
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63002
- OSV: https://osv.dev/vulnerability/CVE-2026-63002

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63002/
Summaries are generated and may contain mistakes; the official description above is the record.