CVE-2026-16408
Integer overflow in Firefox media playback enabling remote code execution.
Is CVE-2026-16408 being exploited?
Not confirmed. CVE-2026-16408 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 0.43% probability of exploitation in the next 30 days.
How severe is CVE-2026-16408?
CVE-2026-16408 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-2026-16408?
Yes. A fix has been recorded for CVE-2026-16408. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-16408 affect?
CVE-2026-16408 affects Mozilla Firefox < 153. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-16408?
Update all Firefox instances to 153+ immediately; block untrusted media.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution via crafted media or webpage during playback; attacker can execute arbitrary code on user systems.
Immediate action required