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.
History

Mon, 13 Apr 2026 14:30:00 +0000

Type Values Removed Values Added
Description 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 affects Firefox < 149.0.2 and Thunderbird < 149.0.2. 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.

Mon, 13 Apr 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Wed, 08 Apr 2026 12:30:00 +0000


Tue, 07 Apr 2026 20:45:00 +0000

Type Values Removed Values Added
Description 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 affects Firefox < 149.0.2. 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 affects Firefox < 149.0.2 and Thunderbird < 149.0.2.
First Time appeared Mozilla
Mozilla firefox
Mozilla thunderbird
Weaknesses CWE-787
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
Vendors & Products Mozilla
Mozilla firefox
Mozilla thunderbird
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Tue, 07 Apr 2026 15:15:00 +0000

Type Values Removed Values Added
Description 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 affects Firefox < 149.0.2.
Title Memory safety bugs fixed in Firefox 149.0.2 and Thunderbird 149.0.2
References

cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published: 2026-04-07T12:43:15.857Z

Updated: 2026-04-13T13:51:36.700Z

Reserved: 2026-04-07T12:43:15.436Z

Link: CVE-2026-5735

cve-icon Vulnrichment

Updated: 2026-04-13T13:20:55.188Z

cve-icon NVD

Status : Modified

Published: 2026-04-07T13:16:47.763

Modified: 2026-04-13T15:17:47.010

Link: CVE-2026-5735

cve-icon Redhat

Severity : Important

Publid Date: 2026-04-07T12:43:15Z

Links: CVE-2026-5735 - Bugzilla