CVE-2026-16364 -- CVSS 9.1 Vulnerability Briefing

CVE-2026-16364 | CVSS 9.1 (Critical) | Exploit: No known exploit

What Is It

CVE-2026-16364 is an incorrect boundary-conditions vulnerability in Mozilla Firefox and Mozilla Thunderbird's Audio/Video: Playback component, affecting the processing of audio or video playback content.

Technical Detail

The flaw involves improper handling of boundaries within the playback component. An attacker may be able to trigger the issue by causing a user to process specially crafted audio or video content through an affected application. The available advisory information does not specify the precise memory-safety condition or the confirmed post-exploitation impact, but the vulnerability has a CVSS score of 9.1 and should be treated as critical.

Exploitation Status

No known exploit has been reported as of July 28, 2026. CVE-2026-16364 is not listed in the CISA Known Exploited Vulnerabilities catalog, and there is no confirmed evidence of active exploitation in the wild.

Who Is Targeting This

No specific threat actor attribution at this time.

What To Do

Update Mozilla Firefox and Mozilla Thunderbird to version 153 or later as a priority. Organizations should use centralized software inventory and patch-management tools to identify systems running earlier versions and verify successful deployment. No vendor-supported workaround or specific detection signature has been confirmed; monitor endpoint and application telemetry for unusual browser or mail-client crashes associated with audio or video playback, while recognizing that crash activity alone does not confirm exploitation.