During the plaintext phase of the STARTTLS connection setup, protocol commands could have been injected and evaluated within the encrypted session. This vulnerability affects Thunderbird < 78.7.
Exploitability
AV:NAC:LPR:NUI:RScope
S:UImpact
C:HI:HA:H8.8/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H