Inefficient regular expression complexity in xmldom - CVE-2026-83606
Published: August 14, 2026 / Updated: September 2, 2026
Vulnerability identifier: #VU142547
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-83606
CWE-ID: CWE-1333
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to inefficient regular expression complexity in the processing-instruction grammar regex in lib/grammar.js when parsing an unterminated processing instruction. A remote attacker can send a specially crafted XML document to cause a denial of service.
The issue is reachable through DOMParser.parseFromString under default options and can stall the Node.js event loop during parsing.
Affected software
xmldom
How to mitigate CVE-2026-83606
Install security update from vendor's website.
xmldom - update to 0.9.11