CVE-2026-59851 — HIGH (8.8)

Vulnerability 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.

CVSS Score

8.8

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Libssh	Libssh	-
Redhat	Hardened Images	-
Redhat	Enterprise Linux	10.0

Related Weaknesses (CWE)

CWE-863

References

https://access.redhat.com/errata/RHSA-2026:42922Issue Tracking
https://access.redhat.com/errata/RHSA-2026:55855
https://access.redhat.com/security/cve/CVE-2026-59851Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2498184Issue TrackingVendor Advisory

FAQ

What is CVE-2026-59851?

CVE-2026-59851 is a vulnerability with a CVSS score of 8.8 (HIGH). 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, al...

How severe is CVE-2026-59851?

CVE-2026-59851 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-59851?

Check the references section above for vendor advisories and patch information. Affected products include: Libssh Libssh, Redhat Hardened Images, Redhat Enterprise Linux.