CVE-2026-59998: CWE-573 Improper Following of Specification by Caller in OpenBSD OpenSSH
sshd in OpenSSH before 10.4 has an undocumented security-relevant behavior: GSSAPIStrictAcceptorCheck has no value if the server is in Windows Active Directory.
AI Analysis
Technical Summary
The vulnerability CVE-2026-59998 affects OpenSSH versions prior to 10.4 on OpenBSD. It involves an undocumented behavior where the GSSAPIStrictAcceptorCheck configuration option does not function as intended when the SSH server is part of a Windows Active Directory environment. This improper adherence to specification by the caller (CWE-573) could lead to reduced security enforcement in GSSAPI authentication scenarios. No specific exploit details or attack vectors are provided, and no known exploits are reported in the wild.
Potential Impact
The impact is limited to a potential weakening of GSSAPI authentication checks in environments where OpenSSH servers are integrated with Windows Active Directory. This could lead to reduced assurance in the authentication process, affecting confidentiality and integrity to a low degree. There is no reported impact on availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch information is currently available. Until a patch is released, administrators should be aware of this behavior when using GSSAPI authentication with Windows Active Directory and consider alternative authentication configurations or additional compensating controls.
CVE-2026-59998: CWE-573 Improper Following of Specification by Caller in OpenBSD OpenSSH
Description
sshd in OpenSSH before 10.4 has an undocumented security-relevant behavior: GSSAPIStrictAcceptorCheck has no value if the server is in Windows Active Directory.
CVSS v3.1
Score 4.8medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-59998 affects OpenSSH versions prior to 10.4 on OpenBSD. It involves an undocumented behavior where the GSSAPIStrictAcceptorCheck configuration option does not function as intended when the SSH server is part of a Windows Active Directory environment. This improper adherence to specification by the caller (CWE-573) could lead to reduced security enforcement in GSSAPI authentication scenarios. No specific exploit details or attack vectors are provided, and no known exploits are reported in the wild.
Potential Impact
The impact is limited to a potential weakening of GSSAPI authentication checks in environments where OpenSSH servers are integrated with Windows Active Directory. This could lead to reduced assurance in the authentication process, affecting confidentiality and integrity to a low degree. There is no reported impact on availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch information is currently available. Until a patch is released, administrators should be aware of this behavior when using GSSAPI authentication with Windows Active Directory and consider alternative authentication configurations or additional compensating controls.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-07-08T00:11:04.817Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4da0cec9d9e3dbe333a4a5
Added to database: 07/08/2026, 00:58:54 UTC
Last enriched: 07/15/2026, 12:14:55 UTC
Last updated: 08/21/2026, 05:29:43 UTC
Views: 141
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