TI-2026-51604 Aliases CVE-2026-73492

Loofah `allowed_uri?` does not detect `javascript:` URIs split by numeric character references without semicolons

LOW 12CWE-184Published 2026-08-12 · Updated 2026-08-14

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: High
Attack requirements: None
Impact type: Cross-site scripting
Confidentiality · integrity · availability: None · None · None
Fix status: Partial Red Hat: 2 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00394 33rd percentileScored 2026-11-07

Fix Partial loofah (flavorjones): 2.25.2Red Hat: 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
flavorjones	loofah	2.25.0 to before 2.25.2	2.25.2	Patch available	CNA

loofah Vendorflavorjones Affected 2.25.0 to before 2.25.2 Fixed in 2.25.2 Patch available CNA

Remediation

Fix · CNA loofah (flavorjones) Fixed in 2.25.2

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat 3scale API Management Platform 2	Affected	No fix planned: Out of support scope
Red Hat Satellite 6	Affected	No fix yet: Fix deferred

Not affected: 2 products

Red Hat 3scale API Management Platform 2
Red Hat Satellite 6

Timeline

2026-10-02 Threatist record created from CVE-2026-73492

References

Other 4

TI-2022-07573 Inefficient Regular Expression Complexity in Loofah CVSS 3.1HIGH 7.5
TI-2022-07575 Uncontrolled Recursion in Loofah CVSS 3.1HIGH 7.5
TI-2018-05825 In the Loofah gem through 2.2.0 for Ruby, non-whitelisted HTML attributes may occur in… CVSS 3.0MEDIUM 6.1
TI-2022-07577 Improper neutralization of data URIs allows XSS in rails-html-sanitizer CVSS 3.1MEDIUM 6.1
TI-2022-07574 Improper neutralization of data URIs may allow XSS in Loofah CVSS 3.1MEDIUM 6.1
TI-2019-11687 Cross-site scripting in Loofah CVSS 3.1MEDIUM 5.4

See all 9 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences