GHSA-mfqj-cqv3-h7xw: typo3/cms-form (CVE-2026-15305)

Package	Ecosystem	Affected	Fixed in
typo3/cms-form	Packagist	>=14.2.0, <14.3.5	14.3.5

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Versions 14.2.0 up to but not including 14.3.5 of the TYPO3 typo3/cms-form package are affected. Forms using FileUpload or ImageUpload elements with allowedMimeTypes configured did not enforce that restriction on the server, so users could upload files of arbitrary MIME types, though PHP files were not accepted. The source does not describe what an uploaded file could then be used for, and it does not say whether any authentication is needed. Upgrade to TYPO3 14.3.5 LTS, which fixes the problem.

Written 31 Oct 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
6.3	Medium	4.0	CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N	CNA (TYPO3)

CISA KEV Not listed.
EPSS 0.0025, the 17th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:06 UTC First seen by agentprime
31 Oct 2026, 14:06 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.