CVE-2026-84640 — One byte overflow read in mail parser
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 Thunderbir…
Published: 2026-09-01 · CVSS: 7.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7