CVE-2026-15305 TYPO3 CMS - Unrestricted File Upload in Form Framework
Attackers can upload malicious files to TYPO3 forms if MIME type restrictions are configured, potentially leading to remote code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-15305?
CVE-2026-15305 is a medium-severity vulnerability in TYPO3 CMS, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Users were able to upload files with arbitrary MIME types to forms using FileUpload or ImageUpload elements with allowedMimeTypes configured. The restriction was not enforced server-side because the MimeTypeValidator was registered during form building before concrete form definition properties were applied, resulting in the validator never being added to the processing pipeline. This issue affects TYPO3 CMS versions 14.2.0-14.3.4.
Weakness: CWE-351
Which versions are affected by CVE-2026-15305?
2 open source packages ship an affected version, including typo3/cms-form.
| Package | Affected | Fixed in |
|---|---|---|
typo3/cms-form Packagist | From 14.2.0 | 14.3.5 |
typo3/cms-form Packagist | From 14.2.0 | 14.3.5 |
How do I fix CVE-2026-15305?
Upgrade typo3/cms-form to 14.3.5 or later.
Is CVE-2026-15305 being exploited?
There is no known exploitation of CVE-2026-15305 in the wild and no public exploit code.
Sources
Also known as GHSA-mfqj-cqv3-h7xw.