Mozilla · Thunderbird Esr · CVE-2026-5734
Name of the Vulnerable Software and Affected Versions
Firefox versions prior to 149.0.2
Firefox ESR versions prior to 140.9.1
Thunderbird versions prior to 149.0.2
Thunderbird ESR versions prior to 140.9.1
Description
Memory safety bugs are present in Firefox and Thunderbird, potentially leading to memory corruption and arbitrary code execution. These bugs were identified in versions ESR 140.9.0, 140.9.0, 149.0.1, and 149.0.1.
Recommendations
Update Firefox to version 149.0.2 or later.
Update Firefox ESR to version 140.9.1 or later.
Update Thunderbird to version 149.0.2 or later.
Update Thunderbird ESR to version 140.9.1 or later.