CVE-2026-59851 (GCVE-0-2026-59851)

Vulnerability from cvelistv5 – Published: 2026-07-21 14:20 – Updated: 2026-07-22 19:06
VLAI
Title
Libssh: libssh: authentication bypass via missing gssapi principal check
Summary
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.
Severity
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
  • CWE-863 - Incorrect Authorization
Assigner
References
URL Tags
https://access.redhat.com/errata/RHSA-2026:42922 vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-59851 vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2498184 issue-trackingx_refsource_REDHAT
Impacted products
Vendor Product Version
Red Hat Red Hat Hardened Images Unaffected: 0.12.1-4.hum1 , < * (rpm)
    cpe:/a:redhat:hummingbird:1
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Red Hat Red Hat Enterprise Linux 10     cpe:/o:redhat:enterprise_linux:10
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Red Hat Red Hat Enterprise Linux 8     cpe:/o:redhat:enterprise_linux:8
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Red Hat Red Hat Enterprise Linux 9     cpe:/o:redhat:enterprise_linux:9
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Date Public
2026-07-21 14:14
Credits
Red Hat would like to thank Aisle Research for reporting this issue.
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.