Vulnerability Details CVE-2026-103500
An attacker could cause a heap buffer overflow by getting a user to open an email that is greater than or equal to 2GB in size. This vulnerability was fixed in Thunderbird 157, Thunderbird 140.17, and Thunderbird 153.4.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 9.8%
CVSS Severity