Description
A flaw was found in libssh. On servers with GSSAPIKeyExchange enabled, the gssapi-keyex path does not verify whether the authenticated Kerberos principal is authorized for the requested local user, allowing authenticated clients to log in as arbitrary users.
Affected products
libssh: libssh; redhat: hardened images; redhat: enterprise linux; redhat: enterprise linux eus; redhat: enterprise linux for els; redhat: enterprise linux for ibm z systems; redhat: enterprise linux for ibm z systems els; redhat: enterprise linux for ibm z systems eus; redhat: enterprise linux for power little endian; redhat: enterprise linux for power little endian els; redhat: enterprise linux for power little endian eus
References4
- access.redhat.com/errata/RHSA-2026:55855 Vendor Advisory
- access.redhat.com/security/cve/CVE-2026-59851 Vendor Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2498184 Issue TrackingVendor Advisory
- access.redhat.com/errata/RHSA-2026:42922 Issue Tracking
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 43 · as of 14 November 2026
- CWE
- CWE-863
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