CVE-2019-19977: Libesmtp Project Libesmtp

Critical severity, CVSS 9.8. EPSS: 2.9% chance of exploitation in the next 30 days.

libESMTP through 1.0.6 mishandles domain copying into a fixed-size buffer in ntlm_build_type_2 in ntlm/ntlmstruct.c, as demonstrated by a stack-based buffer over-read.

Affected products

• Libesmtp Project Libesmtp: up to and including 1.0.6

Published 2019-12-26. Last modified 2026-06-17.