Description
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: URIs whose scheme is split or prefixed with the HTML5 named whitespace character references 	 or 
. CGI.unescapeHTML leaves those references intact, so allowed_uri? reports the URL safe even though a browser decodes and strips the tab or line feed and executes the resulting javascript: URL. 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.
Published: 2026-08-12
Score: 2.3 Low
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-8whx-365g-h9vv Loofah `allowed_uri?` does not detect `javascript:` URIs split by named whitespace character references
History

Thu, 13 Aug 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 13 Aug 2026 10:15:00 +0000

Type Values Removed Values Added
First Time appeared Flavorjones
Flavorjones loofah
Vendors & Products Flavorjones
Flavorjones loofah

Wed, 12 Aug 2026 21:00:00 +0000

Type Values Removed Values Added
Description 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: URIs whose scheme is split or prefixed with the HTML5 named whitespace character references &Tab; or &NewLine;. CGI.unescapeHTML leaves those references intact, so allowed_uri? reports the URL safe even though a browser decodes and strips the tab or line feed and executes the resulting javascript: URL. 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.
Title Loofah `allowed_uri?` does not detect `javascript:` URIs split by named whitespace character references
Weaknesses CWE-184
References
Metrics cvssV4_0

{'score': 2.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}


Subscriptions

Flavorjones Loofah
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-13T13:49:22.724Z

Reserved: 2026-08-12T19:00:33.735Z

Link: CVE-2026-73491

cve-icon Vulnrichment

Updated: 2026-08-13T13:49:14.686Z

cve-icon NVD

Status : Received

Published: 2026-08-12T21:17:42.273

Modified: 2026-08-13T15:20:16.377

Link: CVE-2026-73491

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-13T09:47:44Z

Weaknesses
  • CWE-184

    Incomplete List of Disallowed Inputs