CVE-2026-12295
Sandbox escape in Firefox DOM Navigation component.
Is CVE-2026-12295 being exploited?
Not confirmed. CVE-2026-12295 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 0.39% probability of exploitation in the next 30 days.
How severe is CVE-2026-12295?
CVE-2026-12295 is rated Critical with a CVSS score of 9.6. 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-2026-12295?
Yes. A fix has been recorded for CVE-2026-12295. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-12295 affect?
CVE-2026-12295 affects Mozilla Firefox, Mozilla Firefox ESR, Mozilla Thunderbird, Mozilla Thunderbird ESR. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-12295?
Patch to Firefox 152+/ESR 140.12+ and Thunderbird 152+
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Sandbox escape in DOM Navigation could allow code execution with browser privileges via crafted content.
Immediate action required