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CVE-2026-59851

Libssh: libssh: authentication bypass via missing gssapi principal check

Published: Jul 21, 2026Updated: Jul 30, 2026 Sources: CVE List NVDCWE-863
8.8HIGH
NVD MITRE
EPSS Score
0.3%
Top 80.5%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:NS:UC:HI:HA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-863

Affected Products

Red Hat
commercial·USaka redhat
Red Hat Hardened ImagesOn-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 10On-premOS
Operating Systems / linux-distro
hardened imagesOn-prem
Operating Systems / linux-distro
libssh
oss-projectaka libssh2 (related, sometimes confused)
libsshLibrary
OSS Libraries / generic-library
and 3 more affected products View all →

Exploitability

Official Patch Available
Workaround Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Initial Access
View detailed technique mapping

References

https://access.redhat.com/errata/RHSA-2026:42922
access.redhat.com
https://access.redhat.com/security/cve/CVE-2026-59851
access.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2498184
bugzilla.redhat.com

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