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CVE Radar
HIGH

CVE-2026-83608

CVE-2026-83608 — xmldom: DocType `name` Injection Bypasses requireWellFormed

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.

Published Updated Sources: cvelistV5, GitHub_M

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

<1%

chance of exploitation in 30 days

Affects

Xmldom

xmldom

CVSS base

8.7

HIGH

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

PoC

none · proof-of-concept · active

Automatable

Yes

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Affected scope

The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.

Vendors (1)

Xmldom

Products (1)

xmldom

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Every CVSS base score collected, by source and version
ScoreVersionSeverityExpl.ImpactSource
8.7CVSS 4.0HIGHn/an/acvelistV5

Weakness & attack patterns

  • CWE-91

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

  • Search application, proxy, and WAF logs for requests touching /xmldom, /dom.js.

References

7 on the record

Elsewhere on this site

  • Xmldomevery CVE for this vendor
  • CWE-91other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.