Critical remote-code-execution via audio/video bounds bug in widely used Mozilla Firefox and Thunderbird; high CVSS and broad user base requires org-wide attention.
CVE-2026-16364
Audio/video bounds bug in Firefox/Thunderbird enabling remote code execution via crafted media.
Is CVE-2026-16364 being exploited?
Not confirmed. CVE-2026-16364 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 0.31% probability of exploitation in the next 30 days.
How severe is CVE-2026-16364?
CVE-2026-16364 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-2026-16364?
Yes. A fix has been recorded for CVE-2026-16364. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-16364 affect?
CVE-2026-16364 affects Mozilla Firefox < 153, Mozilla Thunderbird < 153, All supported platforms (Windows/macOS/Linux). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-16364?
Update Firefox and Thunderbird to 153+ immediately; block/untrusted media until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Crafted media can trigger buffer overflow, allowing remote code execution and potential full system compromise.
Immediate action required