CVE-2026-73492

LowCVSS 2.3

Published: 12/08/2026(UTC)Updated: 14/08/2026(UTC)Translated: 13/08/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.25%

16th percentile - higher than 16% of all known CVEs

Summary

Loofah from 2.25.0 until 2.25.2 does not reject javascript: or vbscript: URIs whose scheme is split by semicolon-less numeric character references such as &#58, &#9, &#10, or &#13. CGI.unescapeHTML leaves these references encoded, so allowed_uri? reports the URL safe even though a browser decodes an encoded colon or strips encoded whitespace and executes the resulting URI scheme. This issue affects only callers that pass HTML-encoded strings directly to allowed_uri?; Loofah's default sanitize() path is not affected. This issue is fixed in version 2.25.2.

Risk Assessment

An attacker could exploit this vulnerability to inject malicious JavaScript or VBScript, potentially leading to XSS attacks or data theft if the application uses allowed_uri? with unprocessed data.

Recommendation

Update Loofah to version 2.25.2 or later and avoid passing encoded strings directly to allowed_uri?.

Original NVD description (English source)

Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. From 2.25.0 until 2.25.2, Loofah::HTML5::Scrub.allowed_uri? does not reject javascript: or vbscript: URIs whose scheme is split by semicolon-less numeric character references such as &#58, &#9, &#10, or &#13. CGI.unescapeHTML leaves these references encoded, so allowed_uri? reports the URL safe even though a browser decodes an encoded colon or strips encoded whitespace and executes the resulting URI scheme. This issue affects only callers that pass HTML-encoded strings directly to allowed_uri?; Loofah's default sanitize() path is not affected. This issue is fixed in version 2.25.2.