CVE-2026-59998

EUVD-2026-42141
sshd in OpenSSH before 10.4 has an undocumented security-relevant behavior: GSSAPIStrictAcceptorCheck has no value if the server is in Windows Active Directory.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
mitreCNA
4.8 MEDIUM
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 7%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
openbsdopenssh
𝑥
< 10.4
CNA
Debian logo
Debian Releases
Debian Product
Codename
openssh
bookworm
vulnerable
bookworm (security)
vulnerable
bullseye
vulnerable
bullseye (security)
vulnerable
forky
vulnerable
sid
1:10.4p1-1
fixed
trixie
vulnerable
trixie (security)
vulnerable
Common Weakness Enumeration
Vulnerability Media Exposure
References
https://marc.info/?l=openssh-unix-dev&m=178333966933090&w=2
https://www.openssh.org/releasenotes.html#10.4p1
https://www.openwall.com/lists/oss-security/2026/07/06/5