VulnTideExploited vulnerabilities, by vendor. Data as of .
Not in CISA KEVPublished CVSS 8.8 highEPSS 0.5% probability of exploitation in 30 daysFound by AI: AISLE
Red Hat

CVE-2026-59851: Libssh: libssh: authentication bypass via missing gssapi principal check

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?
0.5%

EPSS score, percentile 42 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?
8.8 High

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (2)

Which versions are affected?

Unaffected 0:0.12.0-3.el10_2; 0.12.1-4.hum1

Versions by product

Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.

What to do

Workaround (from the CVE record)

Disable GSSAPIKeyExchange.

Advisories and patches

This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Red Hat Red Hat Enterprise Linux 10
StatusVersions
Unaffected0:0.12.0-3.el10_2

Versions not listed are: affected.

Red Hat Red Hat Hardened Images
StatusVersions
Unaffected0.12.1-4.hum1

Versions not listed are: affected.

Red Hat Red Hat Enterprise Linux 8
StatusVersions

Versions not listed are: unaffected.

Red Hat Red Hat Enterprise Linux 9
StatusVersions

Versions not listed are: unaffected.

Versions the record lists as unaffected: 0:0.12.0-3.el10_2, 0.12.1-4.hum1.

Source: CVE List, as of . About the data.

About this vulnerability

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.

Summary: CVE record, as of .

  • CISA has not added CVE-2026-59851 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
  • The CVE record was published on 21 Jul 2026.
  • The CVE record carries a CVSS v3.1 base score of 8.8 (High), given by its CNA.
  • FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.5% (percentile 42), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
  • CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact total.
  • The credits in the CVE record name AISLE as finder.

Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.

Description

Libssh: libssh: authentication bypass via missing gssapi principal check

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.

Source: CVE List, as of . About the data.

Weakness

CWE-863

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.

Timeline

DateEvent
CVE record published
CVE record last updated

References

2

Known exploited Red Hat vulnerabilities

  • CVE-2015-3246: Red Hat Libuser Race Condition Vulnerability (added )
  • CVE-2015-5287: Red Hat Automatic Bug Reporting Tool Privilege Escalation Vulnerability (added )
  • CVE-2018-14667: Red Hat JBoss RichFaces Framework Expression Language Injection Vulnerability (added )
  • CVE-2021-3560: Red Hat Polkit Incorrect Authorization Vulnerability (added )
  • CVE-2021-4034: Red Hat Polkit Out-of-Bounds Read and Write Vulnerability (added )