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Fencer Intel
medium 4.7

CVE-2026-126208 json

Loofah: SVG `<textPath>` and `<mpath>` bypass local-reference restriction

published 13d ago modified 2d ago also EUVD-2026-124715 , GHSA-345x-3rq2-jfrm

cvss
4.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

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.

Patch / fix

  • rubygems loofah 2.25.3

Is CVE-2026-126208 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2d ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-14).

CVSS scores

assigned by version score vector
CNA 3.1 4.7 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N
GitHub 3.1 4.7 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
rubygems loofah
<2.25.3
2.25.3

Affected products

  • flavorjones loofah

Classification

Weakness
  • CWE-178 Improper Handling of Case Sensitivity
  • CWE-184 Incomplete List of Disallowed Inputs

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of flavorjones/loofah published their own advisory on GitHub. Reviewed sources take precedence over it.