Widely used browser; DOM mitigation bypass can enable sandbox escape/RCE across enterprises and consumer endpoints — high-impact and newsworthy.
CVE-2026-16394
Mitigation bypass in Firefox DOM enabling potential sandbox escape or remote code execution.
Is CVE-2026-16394 being exploited?
Not confirmed. CVE-2026-16394 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 0.25% probability of exploitation in the next 30 days.
How severe is CVE-2026-16394?
CVE-2026-16394 is rated Critical with a CVSS score of 9.1. 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-2026-16394?
Yes. A fix has been recorded for CVE-2026-16394. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-16394 affect?
CVE-2026-16394 affects Mozilla Firefox <153. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-16394?
Upgrade to Firefox 153 or later immediately; update enterprise images and endpoints.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Bypass of DOM mitigations via crafted web content allowing sandbox escape or remote code execution and full endpoint compromise.
Immediate action required