CVE-2026-59998: OpenBSD OpenSSH

Medium severity, CVSS 6.5. EPSS: 0.2% chance of exploitation in the next 30 days.

sshd in OpenSSH before 10.4 has an undocumented security-relevant behavior: GSSAPIStrictAcceptorCheck has no value if the server is in Windows Active Directory.

Affected products

• OpenBSD OpenSSH: before 10.4 (fixed in 10.4)

Published 2026-07-08. Last modified 2026-07-09.