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01 Record

CVE-2026-59998

sshd in OpenSSH before 10.4 has an undocumented security-relevant behavior: GSSAPIStrictAcceptorCheck has no value if the server is in Windows Active Directory.

MediumPUBLISHEDCNA: mitre
CNA base score4.8 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
View raw JSON

02 Description

sshd in OpenSSH before 10.4 has an undocumented security-relevant behavior: GSSAPIStrictAcceptorCheck has no value if the server is in Windows Active Directory.

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.18% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 7.4% of scored records. A rank, not a probability.
NVD base score
6.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD analysis status
Analyzed. NVD last modified this record on 2026-10-25.
Red Hat severity
Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-07-08 00:11Z3 MO AGO
Last updated
2026-07-08 13:48Z3 MO AGO
Reserved
2026-07-08
Assigning CNA
mitre
Record state
PUBLISHED
Severity
Medium (CVSS 4.8)
CNA CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Weaknesses
  • CWE-573Improper Following of Specification by CallerClass
  • CWE-909Missing Initialization of ResourceClass
Data version
5.2
Document digest
edeccddd4e6746baa147b1b0e1a2859ae9aec6d99f5fcaaf20707c8c5607e3db

05 Affected products

VendorProductVersionsPlatforms
OpenBSDOpenSSH0 to < 10.4—

06 References

07 Fixed in

AlmaLinux 8

  • openssh
    Fixed in 8.0p1-34.el8_10
  • openssh-askpass
    Fixed in 8.0p1-34.el8_10
  • openssh-cavs
    Fixed in 8.0p1-34.el8_10
  • openssh-clients
    Fixed in 8.0p1-34.el8_10
  • openssh-keycat
    Fixed in 8.0p1-34.el8_10
  • openssh-ldap
    Fixed in 8.0p1-34.el8_10
  • openssh-server
    Fixed in 8.0p1-34.el8_10
  • pam_ssh_agent_auth
    Fixed in 0.10.3-8.34.el8_10

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 9

  • openssh
    Fixed in 9.9p1-13.el9_8.alma.1
  • openssh-askpass
    Fixed in 9.9p1-13.el9_8.alma.1
  • openssh-clients
    Fixed in 9.9p1-13.el9_8.alma.1
  • openssh-keycat
    Fixed in 9.9p1-13.el9_8.alma.1
  • openssh-server
    Fixed in 9.9p1-13.el9_8.alma.1
  • pam_ssh_agent_auth
    Fixed in 0.10.4-8.13.el9_8.alma.1

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 10

  • openssh
    Fixed in 9.9p1-29.el10_2.alma.1
  • openssh-askpass
    Fixed in 9.9p1-29.el10_2.alma.1
  • openssh-clients
    Fixed in 9.9p1-29.el10_2.alma.1
  • openssh-keycat
    Fixed in 9.9p1-29.el10_2.alma.1
  • openssh-keysign
    Fixed in 9.9p1-29.el10_2.alma.1
  • openssh-server
    Fixed in 9.9p1-29.el10_2.alma.1

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 8

  • openssh
    Fixed in 8.0p1-34.el8_10
  • openssh-askpass
    Fixed in 8.0p1-34.el8_10
  • openssh-cavs
    Fixed in 8.0p1-34.el8_10
  • openssh-clients
    Fixed in 8.0p1-34.el8_10
  • openssh-keycat
    Fixed in 8.0p1-34.el8_10
  • openssh-ldap
    Fixed in 8.0p1-34.el8_10
  • openssh-server
    Fixed in 8.0p1-34.el8_10
  • pam_ssh_agent_auth
    Fixed in 0.10.3-8.34.el8_10

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 9

  • openssh
    Fixed in 9.9p1-13.el9_8.alma.1
  • openssh-askpass
    Fixed in 9.9p1-13.el9_8.alma.1
  • openssh-clients
    Fixed in 9.9p1-13.el9_8.alma.1
  • openssh-keycat
    Fixed in 9.9p1-13.el9_8.alma.1
  • openssh-server
    Fixed in 9.9p1-13.el9_8.alma.1
  • pam_ssh_agent_auth
    Fixed in 0.10.4-8.13.el9_8.alma.1

Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 10

  • openssh
    Fixed in 9.9p1-29.el10_2.alma.1
  • openssh-askpass
    Fixed in 9.9p1-29.el10_2.alma.1
  • openssh-clients
    Fixed in 9.9p1-29.el10_2.alma.1
  • openssh-keycat
    Fixed in 9.9p1-29.el10_2.alma.1
  • openssh-keysign
    Fixed in 9.9p1-29.el10_2.alma.1
  • openssh-server
    Fixed in 9.9p1-29.el10_2.alma.1

Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • openssh
    No fix yet

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • openssh
    No fix yet

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • openssh
    Fixed in 1:10.4p1-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 18.04 LTS

  • openssh-ssh1
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 20.04 LTS

  • openssh-ssh1
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 22.04 LTS

  • openssh
    Fixed in 1:8.9p1-3ubuntu0.16
  • openssh-ssh1
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 24.04 LTS

  • openssh
    Fixed in 1:9.6p1-3ubuntu13.18
  • openssh-ssh1
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 25.10

  • openssh
    No fix yet
  • openssh-ssh1
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.04 LTS

  • openssh
    Fixed in 1:10.2p1-2ubuntu3.4
  • openssh-ssh1
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.10

  • openssh-ssh1
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 14.04 LTS

  • openssh
    Fixed in 1:6.6p1-2ubuntu2.13+esm4
    Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 16.04 LTS

  • openssh
    Fixed in 1:7.2p2-4ubuntu2.10+esm10
    Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 18.04 LTS

  • openssh
    Fixed in 1:7.6p1-4ubuntu0.7+esm6
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 20.04 LTS

  • openssh
    Fixed in 1:8.2p1-4ubuntu0.13+esm3
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS-preview 22.04 LTS

  • openssh
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS-updates 16.04 LTS

  • openssh
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS-updates 18.04 LTS

  • openssh
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS-updates 20.04 LTS

  • openssh
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS-updates 22.04 LTS

  • openssh
    Fixed in 1:8.9p1-3ubuntu0.16+Fips3
    Available with Ubuntu Pro: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS-updates 24.04 LTS

  • openssh
    Fixed in 1:9.6p1-3ubuntu13.18+Fips1
    Available with Ubuntu Pro: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS 16.04 LTS

  • openssh
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS 18.04 LTS

  • openssh
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS 20.04 LTS

  • openssh
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.