CVE-2026-126208

MEDIUMCVSS 4.7/10

Last modified

CVE-2026-126208 is a medium-severity vulnerability rated 4.7/10 on the CVSS scale. Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. Prior to 2.25.3, Loofah's SVG_ALLOW_LOCAL_HREF safelist lists textPath with lowercase spelling that does not match the HTML5 parser's element name and omits mpath, so external href and xlink:href values on those elements survive sanitization.

Description

Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. Prior to 2.25.3, Loofah's SVG_ALLOW_LOCAL_HREF safelist lists textPath with lowercase spelling that does not match the HTML5 parser's element name and omits mpath, so external href and xlink:href values on those elements survive sanitization. Firefox fetches the attacker-chosen URL when a viewer renders the content, which can disclose the viewer's IP address, user agent, referrer, and access to hosts routable only from the viewer's network. Chrome and WebKit do not fetch these references, and the impact is a network request rather than script execution. The rails-html-sanitizer PermitScrubber reuses the affected safelist when SVG elements are permitted. This issue is fixed in version 2.25.3.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
flavorjonesloofah< 2.25.3

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-126208?
Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. Prior to 2.25.3, Loofah's SVG_ALLOW_LOCAL_HREF safelist lists textPath with lowercase spelling that does not match the HTML5 parser's element name and omits mpath, so external href and xlink:href values on those elements survive sanitization. Firefox fetches the attacker-chosen URL when a viewer renders the content, which can disclose the viewer's IP address, user agent, referrer, and access to hosts routable only from the viewer's network. Chrome and WebKit do not fetch these references, and the impact is a network request rather than script execution. The rails-html-sanitizer PermitScrubber reuses the affected safelist when SVG elements are permitted. This issue is fixed in version 2.25.3.
How severe is CVE-2026-126208?
CVE-2026-126208 has a CVSS score of 4.7/10 (MEDIUM severity).
How do I fix CVE-2026-126208?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST