CVE-2026-15305
mediumpriority · track · 0EPSS 0.003 · 17 %ileDEEUUSEPSS · scored 2026-10-26
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.7–6.3
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (4)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-2337TYPO3 Core: Schwachstelle ermöglicht Umgehen von SicherheitsvorkehrungenDeutsch2026-07-14csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in TYPO3 Core ausnutzen, um Sicherheitsvorkehrungen zu umgehen.
- GHSA-mfqj-cqv3-h7xwTYPO3 CMS - Unrestricted File Upload in Form Framework2026-08-31ghsa · osvUS
### Problem Users were able to upload files with arbitrary MIME types to forms using _FileUpload_ or _ImageUpload_ elements with _allowedMimeTypes_ configured - uploading PHP files was **not** possible. 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. ### Solution Update to TYPO3 version 14.3.5 LTS that fixes the problem described. ### Credits Thanks to Sébastien Convers for reporting this issue, and to Josua Vogel and Oliver Hader for fixing it.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (7)
External citations — patches, advisories, analysis.
- https://typo3.org/security/advisory/typo3-core-sa-2026-020cnnvd
- https://github.com/TYPO3/typo3/commit/817ad41cc9dd28aac0fc4d0fe16fc25d46dd554aenisa_euvd
- https://github.com/TYPO3/typo3/commit/cfda21050398eb145211a4fa6f9988f10e43e10benisa_euvd
- https://typo3.org/security/advisory/typo3-core-sa-2026-020enisa_euvd
- https://github.com/TYPO3/typo3/commit/817ad41cc9dd28aac0fc4d0fe16fc25d46dd554anvd
- https://github.com/TYPO3/typo3/commit/cfda21050398eb145211a4fa6f9988f10e43e10bnvd
- https://typo3.org/security/advisory/typo3-core-sa-2026-020nvd
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