Critical (9.8) in exim exim. EPSS 4.2% chance of exploitation in the next 30 days.
Exim 4 before 4.94.2 allows Buffer Underwrite that may result in unauthenticated remote attackers executing arbitrary commands, because smtp_ungetc was only intended to push back characters, but can actually push back non-character error codes such as EOF.
Severity
CVSS 3.1
9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
4.2% chance of exploitation in the next 30 days; higher than 90% of CVEs (scores of 2026-10-31)