Mozilla product security update advisory

Mozilla has released a security update that addresses a vulnerability in Firefox. affected products are Firefox versions below 150.0.3.

Affected vulnerabilities

• CVE-2026-8389: A JIT miscompilation vulnerability in the JavaScript Engine’s Just-In-Time (JIT) component, a component that speeds up code at runtime.
• CVE-2026-8390: A post-release use vulnerability in the **WebAssembly (a technology that enables high-performance execution in browsers) component of JavaScript.

What to do

vulnerability patches have been made available in the latest update. users of affected products should follow the instructions on the reference site to update to Firefox 150.0.3.

Note

• Security Vulnerabilities fixed in Firefox 150.0.3.
• https://www.mozilla.org/en-US/security/advisories/mfsa2026-45/