What’s Vulnerable › Vulnerabilities

CVE-2026-83616: xmldom: Processing Instruction Target Injection Bypasses requireWellFormed

• Severity: high (CVSS 8.7 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-01 · updated 2026-09-08
• Weakness: CWE-91

Description

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, Document.createProcessingInstruction(target, data) in lib/dom.js accepts an unvalidated target, while the requireWellFormed: true serializer checks only for a colon and the reserved case-insensitive xml name on 0.9.x and performs no target check on 0.8.x. Because serialization emits <?target data?>, a target containing >, ?, whitespace, or another invalid XML-name character can break the processing-instruction boundary and inject XML structure. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.

Affected products

• xmldom: through 0.6.0; from 0.7.0, < 0.8.15; from 0.9.0, < 0.9.12

References

• https://github.com/xmldom/xmldom/commit/1cde3e31a07c41c87cfd368d6946aa477f16b4f9
• https://github.com/xmldom/xmldom/commit/3b694872bcb5c7e3cbadba961a4be2488750ce5b
• https://github.com/xmldom/xmldom/pull/1071
• https://github.com/xmldom/xmldom/pull/1072
• https://github.com/xmldom/xmldom/releases/tag/0.8.15
• https://github.com/xmldom/xmldom/releases/tag/0.9.12
• https://github.com/xmldom/xmldom/security/advisories/GHSA-c7q8-3ch8-vqpv
• https://github.com/xmldom/xmldom/security/advisories/GHSA-c7q8-3ch8-vqpv

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