Remote code execution in Mozilla Firefox (widely deployed browser) via media parsing; high-impact on many organizations and merits broad IT alerting.
CVE-2026-16395
Integer overflow in Firefox audio/video parsing enables remote code execution.
Is CVE-2026-16395 being exploited?
Not confirmed. CVE-2026-16395 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 0.34% probability of exploitation in the next 30 days.
How severe is CVE-2026-16395?
CVE-2026-16395 is rated Critical with a CVSS score of 9.8. 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-2026-16395?
Yes. A fix has been recorded for CVE-2026-16395. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-16395 affect?
CVE-2026-16395 affects Mozilla Firefox < 153 (all platforms). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-16395?
Upgrade to Firefox 153+ immediately; block/scan untrusted media.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution via crafted audio/video file exploiting integer overflow in Firefox media parser, potentially full system compromise.
Immediate action required