Mozilla Firefox Security Updates – 26 February 2026

Mozilla has released an updated Firefox version 148, Firefox ESR versions 115.33, and 140.8 to fix multiple vulnerabilities.

The addressed vulnerabilities could allow the attacker to bypass security restrictions, obtain sensitive information, or execute arbitrary code and gain access to the affected system.

Sample of the addressed vulnerabilities:

1. Mozilla Sandbox Escape in the Storage: IndexedDB Component (CVE-2026- 2768):

  • CVSS: 10.0
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Consequences: Bypass Security

2. Mozilla Use-after-free in the JavaScript Engine Component (CVE-2026-2765):

  • CVSS: 9.8
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Consequences: Gain Access
Vulnerabilities
Mitigations

The enterprise should deploy this patch as soon as the testing phase is completed.

Mozilla Firefox Security Advisory

References