CVE-2026-4729

CRITICAL

Memory safety bugs fixed in Firefox 149 and Thunderbird 149

Title source: cna
STIX 2.1

Description

Memory safety bugs present in Firefox 148 and Thunderbird 148. 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 and Thunderbird 149.

Scores

CVSS v3 9.8
EPSS 0.0002
EPSS Percentile 6.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-120
Status published
Products (6)
mozilla/firefox < 149.0
Mozilla/Firefox 149
Mozilla/Firefox unspecified - 149
mozilla/thunderbird < 149.0
Mozilla/Thunderbird 149
Mozilla/Thunderbird unspecified - 149
Published Mar 24, 2026
Tracked Since Mar 24, 2026