XML markup injection via unvalidated doctype name
Published Sep 1, 2026 · Updated Sep 1, 2026
XML injection in xmldom packages allows attackers to inject sibling markup through an attacker-controlled DocumentType name. The DOCUMENT_TYPE_NODE serializer validates sibling fields but emits name verbatim, so a greater-than sign or whitespace terminates the doctype and inserts subsequent XML or XHTML. Exploitation requires an application to place attacker-controlled data in DocumentType.name and serialize it; injected markup can alter XML structure or execute script when consumed as XHTML.
Summary
What happened
XML injection in xmldom packages allows attackers to inject sibling markup through an attacker-controlled DocumentType name. The DOCUMENT_TYPE_NODE serializer validates sibling fields but emits name verbatim, so a greater-than sign or whitespace terminates the doctype and inserts subsequent XML or XHTML. Exploitation requires an application to place attacker-controlled data in DocumentType.name and serialize it; injected markup can alter XML structure or execute script when consumed as XHTML.
The record
- CVE
- CVE-2026-83608
- Published
- Sep 1, 2026
- Updated
- Sep 1, 2026
- Vendor
- xmldom
- Product
- xmldom
- Classifications
- CWE-91, CAPEC-250
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 1, 2026CVE publishedPublication date reported by the CVE source.
- Sep 1, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=<= 0.6.0
- Affected versionversion=>= 0.7.0, < 0.8.15
- Affected versionversion=>= 0.9.0, < 0.9.12
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- Upstream DocumentType.name injection proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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