Cross-site scripting in Loofah - CVE-2026-73490
Published: November 6, 2026
Vulnerability identifier: #VU159818
CSH Severity: Medium
CVSS v4: 2.1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-73490
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows an unauthenticated remote attacker to execute scripts in the context of a sanitized document viewed by a victim.
The vulnerability exists due to Loofah's HTML5 sanitizer applying local-reference restrictions to SVG xlink:href but not href when sanitizing user-supplied SVG with its default allowlist. An unauthenticated remote attacker can submit an SVG use element referencing a same-origin external SVG containing scripts, potentially causing execution when the victim views the sanitized content.
Affected software
Loofah
How to mitigate CVE-2026-73490
Install security update from vendor's website.
Loofah - update to 2.25.2