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Fencer Intel
low 2.0

CVE-2026-126064 json

Nokogiri: Possible Use-After-Free when setting an attribute value via `Nokogiri::XML::Node#[]=` or `#lang=`

published yesterday modified yesterday also GHSA-3w22-6jfg-527w , EUVD-2026-122836

cvss
2.0
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.5, the CRuby native extension can leave Ruby wrappers pointing to freed memory when Nokogiri::XML::Node#[]= or Nokogiri::XML::Node#lang= replaces an existing attribute value after code has accessed the attribute's child nodes. Replacing the value frees native child nodes while their wrappers remain reachable, and later use of those wrappers can cause an invalid read or process segfault. JRuby is not affected. This issue is fixed in version 1.19.5.

Patch / fix

  • rubygems nokogiri 1.19.5

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-126064 updated cvss 2.5

nokogiri: nokogiri: Denial of Service via use-after-free when replacing attribute values

  • Red Hat 3scale API Management Platform 2 3scale-amp2/zync-rhel9, 3scale-amp2/system-rhel8, 3scale-amp2/system-rhel9, 3scale-amp2/backend-rhel8, 3scale-amp2/toolbox-rhel9
    affected: workaround, no fix available, no fix planned “Out of support scope”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
yesterday

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 2.0 CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CNA 4.0 2.0 CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
rubygems nokogiri
<1.19.5
1.19.5

Affected products

  • sparklemotion nokogiri

Classification

Weakness

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.