CVE-2026-92238
A maliciously constructed mail header could lead to multiple fields being parsed as one, or potential memory safety violations. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
- Published Sep 15, 2026
- CVSS 9.8 critical
- 0.5% chance of exploitation in the next 30 days (EPSS)
- A fix is available