Bug 2492937 (CVE-2026-57436)

Summary: CVE-2026-57436 nokogiri: rubygem-nokogiri: Nokogiri: Denial of Service via heap use-after-free
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: akostadi, amasferr, anthomas, crizzo, dmayorov, ehelms, eshamard, ggainey, jlledo, jpasqual, juwatts, jvasik, kaycoth, mhulan, nmoumoul, osousa, pantinor, pcreech, rblanco, rchan, rhel-process-autobot, smallamp, tmalecek, tsedmik, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Nokogiri, an open-source library used for processing XML and HTML documents. This vulnerability occurs due to insufficient validation when setting the document's root element, allowing a malicious document to trigger a memory error. This can lead to a heap use-after-free, potentially causing the application to crash and resulting in a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2497303, 2497304    
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Description OSIDB Bzimport 2026-06-25 15:01:58 UTC
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri::XML::Document#root= validated only that the new root was a Nokogiri::XML::Node, allowing a DTD node to be set as the document root. The result is a heap use-after-free during garbage collection or finalization, leading to an invalid memory read or potentially a segfault. This vulnerability is fixed in 1.19.4.