Rapid7

vulnerability

MFSA2026-13 Firefox: Security Vulnerabilities fixed in Firefox 148 (CVE-2026-2778)

Severity
10
CVSS
(AV:N/AC:L/Au:N/C:C/I:C/A:C)
Published
Feb 24, 2026
Added
Feb 25, 2026
Modified
Apr 15, 2026

Description

Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

Solution

mozilla-firefox-upgrade-148_0
Title
Rapid7 Labs

2026 Global Threat Landscape Report

The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.