Bug 2527265

Summary: CVE-2026-83615 jupyterlab: xmldom: Denial of Service via quadratic memory consumption [fedora-all]
Product: [Fedora] Fedora Reporter: Yadnyawalk Tale <ytale>
Component: jupyterlabAssignee: Lumír Balhar <lbalhar>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: rawhideCC: lbalhar, python-packagers-sig, romain.geissler
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["dda5dad3-41a0-4b29-8a67-1592a7558765"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On:    
Bug Blocks: 2526843    

Description Yadnyawalk Tale 2026-09-02 07:49:47 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. Prior to @xmldom/xmldom versions 0.8.15 and 0.9.12, and in xmldom versions 0.1.5 through 0.6.0, appendElement in lib/sax.js uses _copy to clone the complete currentNSMap for each nested element that declares a new namespace prefix. Keeping every ancestor map live on the parse stack creates quadratic peak namespace-map storage, so a small highly compressible XML document can exhaust the process heap before application validation. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.