CVE-2026-83612
xmldom HTML parsing bug causes CPU/memory amplification and potential DoS.
Is CVE-2026-83612 being exploited?
Not confirmed. CVE-2026-83612 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.30% probability of exploitation in the next 30 days.
How severe is CVE-2026-83612?
CVE-2026-83612 is rated High with a CVSS score of 8.7. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-83612?
Yes. A fix has been recorded for CVE-2026-83612. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-83612 affect?
CVE-2026-83612 affects @xmldom/xmldom < 0.9.12, DOMParser.parseFromString() HTML-mode. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-83612?
Upgrade to @xmldom/xmldom v0.9.12+ and validate/sanitize untrusted HTML inputs.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote or local denial-of-service via quadratic CPU/memory amplification when parsing crafted HTML with mixed-case closing tags.
Immediate action required
- affected>= 0.9.0-beta.1 and < 0.9.12
- affected>= 0.9.0-beta.1 and < 0.9.12
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.