CVE-2026-53599
Description
REDAXO is a PHP-based content management system. From 5.18.2 until 5.21.1, rex_mediapool::isAllowedExtension in redaxo/src/addons/mediapool/lib/mediapool.php lets an authenticated backend user with media[upload] permission upload a JPEG/PHP polyglot named shell.php.any.jpg, which web servers with multi-extension PHP handlers can execute as the web-server user. This issue is fixed in version 5.21.1.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Packagist | redaxo/source | >=5.18.2,<5.21.1 | 5.21.1 |
References
- https://github.com/redaxo/core/commit/462e36896bb65d292ba22d711044c23c9cfb0340
- https://github.com/redaxo/core/pull/6538
- https://github.com/redaxo/core/releases/tag/5.21.1
- https://github.com/redaxo/core/security/advisories/GHSA-98pp-vccm-qm25
- https://github.com/advisories/GHSA-98pp-vccm-qm25
- https://github.com/redaxo/core
CWEs
CWE-434
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.