CVE intelligence

CVE-2026-126208

Vulnerability intelligence

Published Nov 12, 2026Sources checked Nov 13, 2026

4.7MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-126208 and is rated Medium severity with a CVSS score of 4.7. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Nov 13, 2026

Release Notes

CISA KEVNot listedBased on the latest collected catalog

EPSSUnavailableNo current score collected

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

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.

Source: NVD