Mozilla security advisory (AV26-401) – Canadian Centre for Cyber Security

Serial number: AV26-401
Date: April 28, 2026

On April 28, 2026, Mozilla published a security advisory to address vulnerabilities in the following products:

• Firefox – versions prior to 150.0.1
• Firefox ESR – versions prior to 140.10.1
• Firefox ESR – versions prior to 115.35.1

The Cyber Centre encourages users and administrators to review the provided web links and apply the necessary updates.