flavorjones Loofah up to 2.25.2 CSS Scrubber Scrub.scrub_css escape output

Summaryinfo

A vulnerability has been found in flavorjones Loofah up to 2.25.2 and classified as problematic. This affects the function Loofah::HTML5::Scrub.scrub_css of the component CSS Scrubber. This manipulation causes escape output. This vulnerability is tracked as CVE-2026-126207. The attack is possible to be carried out remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic was found in flavorjones Loofah up to 2.25.2. Affected by this vulnerability is the function Loofah::HTML5::Scrub.scrub_css of the component CSS Scrubber. The manipulation with an unknown input leads to a escape output vulnerability. The CWE definition for the vulnerability is CWE-116. The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved. As an impact it is known to affect confidentiality. The summary by CVE is:

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::HTML5::Scrub.scrub_css checks only the first parse of a style attribute, then rebuilds CSS with identifier escapes decoded so escaped parentheses, property names, comments, or quotes can become a live url() without a second safety check. An attacker can use list-style to make a viewer's browser request an attacker-chosen URL when content renders, or cursor to make the request on hover. The request can disclose the viewer's IP address, user agent, access timing, and access to internal-network hosts, but no script survives sanitization and the attacker cannot read the response. This issue is fixed in version 2.25.3.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-126207 since 11/10/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

Upgrading to version 2.25.3 eliminates this vulnerability.

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Productinfo

Vendor

• flavorjones

Name

• Loofah

Version

• 2.25.0
• 2.25.1
• 2.25.2

Website

• Product: https://github.com/flavorjones/loofah/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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