Answer in brief
CVE-2026-126207 records a Medium severity (CVSS 4.7) vulnerability in Loofah: CSS url() sanitization bypass via escaped parentheses. The current sources do not mark it as known exploited. The current feed maps flavorjones/loofah (generic), loofah (rubygems). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 4.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps flavorjones/loofah (generic), loofah (rubygems). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| flavorjones/loofahgeneric | <2.25.3 | 2.25.3 |
| loofahrubygems | <2.25.3 | 2.25.3 |
Published upstream
Nov 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 12, 2026
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.
Quoted source text, attributed separately from HOL analysis.