high7.5
CVE-2026-84640
A maliciously constructed mail header could lead to a one byte read past the end of a buffer.
Impact
A maliciously constructed mail header could lead to a one byte read past the end of a buffer. This vulnerability was fixed in Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Mozilla | Thunderbird | before 140.15.0 from 141.0 before 153.2.0 from 154.0 before 155.0 |