CVE-2026-5734

CRITICAL SEVERITY

CVSS Score & Metrics

Base Score

9.8 / 10

Vector String

                                        CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H                                    

Vulnerability Description

Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, 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, Firefox ESR < 140.9.1, Thunderbird < 149.0.2, and Thunderbird < 140.9.1.

Vulnerability Details

Published Date

April 07, 2026

Last Modified

April 13, 2026

CWE ID

CWE-787

Source

NVD

Vendor

mozilla

Product

firefox

External References

https://bugzilla.mozilla.org/buglist.cgi?bug_id=2022369%2C2023026%2C2023545%2C2023555%2C2023958%2C2025422%2C2025468%2C2025492%2C2025505
https://www.mozilla.org/security/advisories/mfsa2026-25/
https://www.mozilla.org/security/advisories/mfsa2026-27/

CVE-2026-5734

CVSS Score & Metrics

Vulnerability Description

Vulnerability Details

External References

Discussion (0)

Add Comment