CVE-2021-21339: TYPO3

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 6.2.57, 7.6.51, 8.7.40, 9.5.25, 10.4.14, 11.1.1 user session identifiers were stored in cleartext - without processing of additional cryptographic hashing algorithms. This vulnerability cannot be exploited directly and occurs in combination with a chained attack - like for instance SQL injection in any other component of the system. This is fixed in versions 6.2.57, 7.6.51, 8.7.40, 9.5.25, 10.4.14, 11.1.1.

Affected products

• TYPO3 TYPO3: from 6.2.0, before 6.2.57 (fixed in 6.2.57); from 7.0.0, before 7.6.51 (fixed in 7.6.51); from 8.0.0, before 8.7.40 (fixed in 8.7.40); from 9.0.0, before 9.5.25 (fixed in 9.5.25); from 10.0.0, before 10.4.14 (fixed in 10.4.14); from 11.0.0, before 11.1.1 (fixed in 11.1.1)

Published 2021-03-23. Last modified 2026-06-17.