CVE-2026-5735

Memory safety bugs fixed in Firefox 149.0.2 and Thunderbird 149.0.2

High · published April 7, 2026

CVSS v3.1
8.1
EPSS
0%
Percentile
39.0
In the wild
Unconfirmed
What it is

Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 149.0.2 and Thunderbird 149.0.2.

The record
Technical detail
CVSS v3.1
8.1 · HIGH
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00461 · 39.0th percentile
Published
2026-04-07T12:43Z
EPSS history
Timeline
  • 07 APR 12:43Z
    Memory safety bugs fixed in Firefox 149.0.2 and Thunderbird 149.0.2
    cvelistv5