CVE-2026-121443

Medium CVSS 5.3

Published 2026-11-03 · last changed 2026-11-03

The fix

We hold no Microsoft remediation data for CVE-2026-121443, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.

What it is

svg-sanitizer from 1.1.0 before 1.1.1 contains a denial of service vulnerability that allows remote attackers to crash requests by submitting SVG input ending inside an unclosed tag. Attackers can upload truncated input like a single '<' to trigger an uncaught ValueError from strpos() in hasElementWithTooManyAttributes() or hasInternalDtdSubset() on PHP 8, failing the request.

Sources

NVD record for CVE-2026-121443

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