Bug 2527271

Summary: CVE-2026-83608 jupyterlab: xmldom: XML Markup Injection via DocType Name Bypass [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
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["406b870f-40fc-478c-b894-35395d40996a"]}
Fixed In Version: Doc Type: ---
Doc Text:
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Documentation: --- CRM:
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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: 2526816    

Description Yadnyawalk Tale 2026-09-02 07:50:34 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 version 0.6.0 and earlier, the DOCUMENT_TYPE_NODE branch in lib/dom.js validates publicId, systemId, and internalSubset under requireWellFormed: true but emits DocumentType.name verbatim. A name containing > or whitespace can terminate the <!DOCTYPE ...> declaration and inject sibling markup; the value can be supplied through createDocumentType() on the 0.8.x and unscoped lines or through a direct DocumentType.name property write on every affected line. The default path and legacy creation-time behavior remain permissive, while the vulnerable strict path fails to enforce an XML Name. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.