Bug 2527273

Summary: CVE-2026-83605 jupyterlab: xmldom: Attribute injection allows client-side script execution [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Yadnyawalk Tale <ytale>
Component: jupyterlabAssignee: Romain Geissler <romain.geissler>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: epel10CC: lbalhar, python-packagers-sig, romain.geissler
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["7b372a53-50b6-4f8e-9e91-cfad8ff29486"]}
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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: 2526811    

Description Yadnyawalk Tale 2026-09-02 07:50:51 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 0.8.14 and 0.9.11, and in xmldom version 0.6.0 and earlier, Element.setAttribute() calls the private _createAttribute(name) path without validating the attribute name, while Document.createAttribute(name) validates against QName. XMLSerializer.serializeToString() emits attribute names verbatim, and requireWellFormed: true did not validate them, so a crafted name can terminate the intended attribute and inject additional attributes, including event handlers, into browser-consumed output; synthesized xmlns:PREFIX declarations expose the same unchecked-name boundary. This issue is fixed in @xmldom/xmldom versions 0.8.14 and 0.9.11; no fixed version is available for xmldom.