Improper Following of Specification by Caller Affecting openssh-portable package, versions [,10.4)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published8 Jul 2026
- disclosed8 Jul 2026
- creditUnknown
Introduced: 8 Jul 2026
CVE-2026-59998 (opens in a new tab)How to fix?
Upgrade openssh-portable to version 10.4 or higher.
Overview
Affected versions of this package are vulnerable to Improper Following of Specification by Caller due to the GSSAPIStrictAcceptorCheck process when the server operates in a Windows Active Directory environment. An attacker can bypass intended authentication checks by exploiting this undocumented behavior.