Description
When ALLOW_INSECURE_RAW_TEXT is enabled, whitespace-variant closing tags (e.g., </style\t>) are not recognized by the sanitizer but accepted by browsers as valid end tags, allowing subsequent content to escape sanitization. This allows bypassing the cross-site scripting prevention mechanism of typo3/html-sanitizer before version 2.3.2.
Problem types
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-436 Interpretation Conflict
Product status
Any version before 2.3.2
Credits
IPC Labs
Oliver Hader
References
typo3.org/security/advisory/typo3-core-sa-2026-006
github.com/...ommit/bd1a88d9b5a5f67f1120ec41084e9c1a0675641c