In Exim before 4.99.2, when JSON lookup is enabled, an out-of-bounds heap write can occur when a JSON operator encounters malformed JSON in an untrusted header, because of an incorrect implementation of \ skipping.
Exploitability
AV:NAC:HPR:NUI:NScope
S:UImpact
C:NI:LA:H6.5/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:HOther