Nokogiri: Possible Use-After-Free in XInclude Processing

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary XInclude substitution performed by Nokogiri::XML::Node#doxinclude replaced each <xi:include in place, freeing the include node along with its children (such as <xi:fallback and its descendants) and any namespaces declared on them. If an application had already exposed one of those nodes or namespaces to Ruby, the corresponding Ruby object was left pointing at freed memory. Using the object could result in invalid reads or writes to memory. Nokogiri 1.19.4 substitutes each <xi:include on a defensive copy by default, so the structures libxml2 frees are never the ones bound to live Ruby objects. Only the CRuby implementation is affected; JRuby is not affected. Severity The Nokogiri maintainers have evaluated this as low severity. Reaching it requires an unusual API-usage pattern that does not arise during normal use. The application must parse a document without XInclude, traverse into an <xi:include subtree to expose its nodes or namespaces to Ruby, and only then invoke…

Published by the source

19 Jun 2026, 16:37 UTC

Last modified by the source

19 Jun 2026, 16:37 UTC

Source last checked

26 Oct 2026, 15:52 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-wfpw-mmfh-qq69

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# Patch Next advisory brief: GHSA-wfpw-mmfh-qq69

Advisory: Nokogiri: Possible Use-After-Free in XInclude Processing
IDs: GHSA-wfpw-mmfh-qq69
Record: https://patchnext.com/advisories/ghsa-wfpw-mmfh-qq69 (revision 1, source checked 26 Oct 2026, 15:52 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: nokogiri 1.19.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems nokogiri: affected < 1.19.4; fixed in 1.19.4

## Suggested inspection (read-only)
- RubyGems nokogiri: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on nokogiri.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-wfpw-mmfh-qq69 (GitHub-reviewed advisory GHSA-wfpw-mmfh-qq69 lists affected ranges: RubyGems nokogiri >=0 <1.19.4)

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