CVE-2021-21340

Name: CVE-2021-21340
Creator: NVD / NIST
Published: 2021-03-23T02:15:12.533+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.4/10EPSS 0.87%

Last modified Jun 17, 2026

CVE-2021-21340 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. 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 database fields used as _descriptionColumn_ are vulnerable to cross-site scripting when their content gets previewed. EPSS estimates a 0.87% chance of exploitation in the next 30 days.

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 database fields used as _descriptionColumn_ are vulnerable to cross-site scripting when their content gets previewed. A valid backend user account is needed to exploit this vulnerability. This is fixed in versions 10.4.14, 11.1.1 .

Metrics

CVSS 3.1

5.4/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.87%

54.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Typo3	Typo3	>= 10.0.0, < 10.4.14
Typo3	Typo3	>= 11.0.0, < 11.1.1

References

https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-fjh3-g8gq-9q92Third Party Advisory
https://packagist.org/packages/typo3/cms-backendRelease Notes, Third Party Advisory
https://typo3.org/security/advisory/typo3-core-sa-2021-007Vendor Advisory
https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-fjh3-g8gq-9q92Third Party Advisory
https://packagist.org/packages/typo3/cms-backendRelease Notes, Third Party Advisory
https://typo3.org/security/advisory/typo3-core-sa-2021-007Vendor Advisory

Timeline

Published: Mar 23, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21340?

How severe is CVE-2021-21340?

CVE-2021-21340 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.87% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21340?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21340?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST