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.
CVE-2026-59851
CVSS base score
8.8 (v3.1)
Severity
HIGH
Attack vector
Network
Weakness
CWE-863
Last modified
November 5, 2026
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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
References
- access.redhat.com Issue Tracking
- access.redhat.com Vendor Advisory
- access.redhat.com Vendor Advisory
- bugzilla.redhat.com Issue Tracking, Vendor Advisory