What’s Vulnerable › Vulnerabilities

CVE-2021-21358: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in typo3/cms-form

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-03-23 · updated 2026-06-17
• Weakness: CWE-79

Description

TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 10.4.14, 11.1.1 it has been discovered that the Form Designer backend module of the Form Framework is vulnerable to cross-site scripting. A valid backend user account with access to the form module is needed to exploit this vulnerability. This is fixed in versions 10.4.14, 11.1.1.

Affected products

• typo3: from 10.2.0 before 10.4.14; from 11.0.0 before 11.1.1 — fixed in 10.4.14, 11.1.1

How to fix

Upgrade to a fixed version: typo3 10.4.14, 11.1.1. Check the vendor advisory for mitigations.

References

• https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-x79j-wgqv-g8h2
• https://packagist.org/packages/typo3/cms-form
• https://typo3.org/security/advisory/typo3-core-sa-2021-004
• https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-x79j-wgqv-g8h2
• https://packagist.org/packages/typo3/cms-form
• https://typo3.org/security/advisory/typo3-core-sa-2021-004

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