Description
Vulnerability in the OpenSSH GSSAPI delta included in various Linux distributions. This vulnerability affects the GSSAPI patches added by various Linux distributions and does not affect the OpenSSH upstream project itself. The usage of sshpkt_disconnect() on an error, which does not terminate the process, allows an attacker to send an unexpected GSSAPI message type during the GSSAPI key exchange to the server, which will call the underlying function and continue the execution of the program without setting the related connection variables. As the variables are not initialized to NULL the code later accesses those uninitialized variables, accessing random memory, which could lead to undefined behavior. The recommended workaround is to use ssh_packet_disconnect() instead, which does terminate the process. The impact of the vulnerability depends heavily on the compiler flag hardening configuration.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Ubuntu | openssh | 1:10.0p1-5ubuntu5 – < 1:10.0p1-5ubuntu5.1, 1:9.6p1-3ubuntu13 – < 1:9.6p1-3ubuntu13.15, 1:8.9p1-3 – < 1:8.9p1-3ubuntu0.14 | 1:10.0p1-5ubuntu5.1 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | openssh | 1:10.2p1-6 | — |
| Debian 13 | openssh | 1:10.0p1-7+deb13u2 | — |
| Debian 12 | openssh | 1:9.2p1-2+deb12u9 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | openssh-ssh1 | No fix yet | — |
| Ubuntu 26.04 LTS | openssh-ssh1 | No fix yet | — |
| Ubuntu 25.10 | openssh | 1:10.0p1-5ubuntu5.1 | — |
| Ubuntu 25.10 | openssh-ssh1 | No fix yet | — |
| Ubuntu 24.04 LTS | openssh | 1:9.6p1-3ubuntu13.15 | — |
| Ubuntu 24.04 LTS | openssh-ssh1 | No fix yet | — |
| Ubuntu 22.04 LTS | openssh | 1:8.9p1-3ubuntu0.14 | — |
| Ubuntu 22.04 LTS | openssh-ssh1 | No fix yet | — |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | openssh-ssh1 | No fix yet | — |
| Ubuntu 18.04 LTS | openssh-ssh1 | No fix yet | — |
| Ubuntu Pro FIPS 20.04 LTS | openssh | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | openssh | No fix yet | — |
| Ubuntu Pro FIPS 16.04 LTS | openssh | No fix yet | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | openssh | 1:9.6p1-3ubuntu13.15+Fips1 | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | openssh | 1:8.9p1-3ubuntu0.14+Fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | openssh | 1:8.2p1-4ubuntu0.fips.0.13.1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | openssh | No fix yet | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | openssh | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | openssh | No fix yet | — |
| Ubuntu Pro 20.04 LTS | openssh | 1:8.2p1-4ubuntu0.13+esm1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | openssh +5 | 9.9p1-13.el10_1 | RHSA-2026:6463 |
| RHEL 9 | openssh +4 | 8.7p1-48.el9_7 | RHSA-2026:6462 |
| RHEL 9 | pam_ssh_agent_auth | 0.10.4-5.48.el9_7 | RHSA-2026:6462 |
| RHEL 8 | openssh +6 | 8.0p1-28.el8_10 | RHSA-2026:6461 |
| RHEL 8 | pam_ssh_agent_auth | 0.10.3-7.28.el8_10 | RHSA-2026:6461 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | openssh +5 | 9.9p1-7.el10_0.2 | RHSA-2026:7107 |
| RHEL 9.6 EUS | openssh +4 | 8.7p1-45.el9_6.2 | RHSA-2026:9415 |
| RHEL 9.6 EUS | pam_ssh_agent_auth | 0.10.4-5.45.el9_6.1 | RHSA-2026:9415 |
| RHEL 9.4 EUS | openssh +4 | 8.7p1-38.el9_4.7 | RHSA-2026:9732 |
| RHEL 9.4 EUS | pam_ssh_agent_auth | 0.10.4-5.38.el9_4.7 | RHSA-2026:9732 |
| RHEL 9.2 E4S | openssh +4 | 8.7p1-30.el9_2.10 | RHSA-2026:10714 |
| RHEL 9.2 E4S | pam_ssh_agent_auth | 0.10.4-5.30.el9_2.10 | RHSA-2026:10714 |
| RHEL 9.0 E4S | openssh +4 | 8.7p1-13.el9_0.2 | RHSA-2026:13750 |
| RHEL 9.0 E4S | pam_ssh_agent_auth | 0.10.4-4.13.el9_0.5 | RHSA-2026:13750 |
| RHEL 8.8 TUS | openssh +6 | 8.0p1-20.el8_8.3 | RHSA-2026:14924 |
| RHEL 8.8 TUS | pam_ssh_agent_auth | 0.10.3-7.20.el8_8.3 | RHSA-2026:14924 |
| RHEL 8.8 E4S | openssh +6 | 8.0p1-20.el8_8.3 | RHSA-2026:14924 |
| RHEL 8.8 E4S | pam_ssh_agent_auth | 0.10.3-7.20.el8_8.3 | RHSA-2026:14924 |
| RHEL 8.6 TUS | openssh +6 | 8.0p1-15.el8_6.4 | RHSA-2026:15893 |
| RHEL 8.6 TUS | pam_ssh_agent_auth | 0.10.3-7.15.el8_6.4 | RHSA-2026:15893 |
| RHEL 8.6 E4S | openssh +6 | 8.0p1-15.el8_6.4 | RHSA-2026:15893 |
| RHEL 8.6 E4S | pam_ssh_agent_auth | 0.10.3-7.15.el8_6.4 | RHSA-2026:15893 |
| RHEL 8.6 AUS | openssh +6 | 8.0p1-15.el8_6.4 | RHSA-2026:15893 |
| RHEL 8.6 AUS | pam_ssh_agent_auth | 0.10.3-7.15.el8_6.4 | RHSA-2026:15893 |
| RHEL 8.4 EUS Long Life | openssh +6 | 8.0p1-7.el8_4.1 | RHSA-2026:15891 |
| RHEL 8.4 EUS Long Life | pam_ssh_agent_auth | 0.10.3-7.7.el8_4.2 | RHSA-2026:15891 |
| RHEL 8.4 AUS | openssh +6 | 8.0p1-7.el8_4.1 | RHSA-2026:15891 |
| RHEL 8.4 AUS | pam_ssh_agent_auth | 0.10.3-7.7.el8_4.2 | RHSA-2026:15891 |
| Red Hat Hardened Images 1 | openssh +6 | 10.2p1-9.hum1 | RHSA-2026:5475 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | openssh +5 | 9.9p1-13.el10_1.alma.1 | ALSA-2026:6463 |
| AlmaLinux 9 | openssh +4 | 8.7p1-48.el9_7.alma.1 | ALSA-2026:6462 |
| AlmaLinux 9 | pam_ssh_agent_auth | 0.10.4-5.48.el9_7.alma.1 | ALSA-2026:6462 |
| AlmaLinux 8 | openssh +6 | 8.0p1-28.el8_10 | ALSA-2026:6461 |
| AlmaLinux 8 | pam_ssh_agent_auth | 0.10.3-7.28.el8_10 | ALSA-2026:6461 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | openssh | 9.9p1-13.el10_1.rocky.0.1 | RLSA-2026:6463 |
| Rocky Linux 9 | openssh | 8.7p1-48.el9_7.rocky.0.1 | RLSA-2026:6462 |
| Rocky Linux 8 | openssh | 8.0p1-28.el8_10 | RLSA-2026:6461 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | openssh +1 | 9.6p1-150600.6.42.1 | SUSE-SU-2026:2371-1 |
| SLES 15 SP6 | openssh +1 | 9.6p1-150600.6.42.1 | SUSE-SU-2026:2371-1 |
| SLES 15 SP5 | openssh +1 | 8.4p1-150300.3.65.1 | SUSE-SU-2026:2375-1 |
| SLES 15 SP4 | openssh +1 | 8.4p1-150300.3.65.1 | SUSE-SU-2026:2375-1 |
| SLES 12 SP5 | openssh +1 | 7.2p2-81.40.1 | SUSE-SU-2026:2395-1 |
| SLES 12 SP5 | openssh8.4 | 8.4p1-8.24.1 | SUSE-SU-2026:2430-1 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | openssh +1 | 10.0p2-160000.6.1 | SUSE-SU-2026:22352-1 |
| SLES for SAP 15 SP6 | openssh +1 | 9.6p1-150600.6.42.1 | SUSE-SU-2026:2371-1 |
| SLES for SAP 15 SP5 | openssh +1 | 8.4p1-150300.3.65.1 | SUSE-SU-2026:2375-1 |
| SLES for SAP 15 SP4 | openssh +1 | 8.4p1-150300.3.65.1 | SUSE-SU-2026:2375-1 |
| SLES 16.0 | openssh +1 | 10.0p2-160000.6.1 | SUSE-SU-2026:22352-1 |
| SLE Micro 6.2 | openssh | 10.0p2-160000.6.1 | SUSE-SU-2026:22268-1 |
| SLE Micro 6.1 | openssh | 9.6p1-slfo.1.1_6.1 | SUSE-SU-2026:22067-1 |
| SLE Micro 6.0 | openssh | 9.6p1-6.1 | SUSE-SU-2026:23249-1 |
| SLE Micro 5.5 | openssh | 8.4p1-150300.3.65.1 | SUSE-SU-2026:2375-1 |
| SLE Micro 5.4 | openssh | 8.4p1-150300.3.65.1 | SUSE-SU-2026:2375-1 |
| SLE Micro 5.3 | openssh | 8.4p1-150300.3.65.1 | SUSE-SU-2026:2375-1 |
| SLE HPC 15 SP5 | openssh +1 | 8.4p1-150300.3.65.1 | SUSE-SU-2026:2375-1 |
| SLE HPC 15 SP4 | openssh +1 | 8.4p1-150300.3.65.1 | SUSE-SU-2026:2375-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | openssh | 10.3p1-6.1 | openSUSE-SU-2026:10937-1 |
| openSUSE Leap 16.0 | openssh +1 | 10.0p2-160000.6.1 | openSUSE-SU-2026:21044-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | openssh +3 | 8.7p1-8.amzn2023.0.18 | ALAS2023-2026-1745 |
| Amazon Linux 2023 | pam_ssh_agent_auth | 0.10.4-4.8.amzn2023.0.18 | ALAS2023-2026-1745 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | openssh +5 | 9.9p1-13.0.1.el10_1 | ELSA-2026-6463 |
| Oracle Linux 9 | openssh +4 | 8.7p1-48.0.1.el9_7 | ELSA-2026-6462 |
| Oracle Linux 9 | pam_ssh_agent_auth | 0.10.4-5.48.0.1.el9_7 | ELSA-2026-6462 |
| Oracle Linux 8 | openssh +6 | 8.0p1-28.0.1.el8_10 | ELSA-2026-6461 |
| Oracle Linux 8 | pam_ssh_agent_auth | 0.10.3-7.28.0.1.el8_10 | ELSA-2026-6461 |
Advisories 38
- SSA-457936 SSA-457936: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.7 Siemens ProductCERT · Nov 10, 2026
- ALSA-2026:6463 Important: openssh security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:6462 Important: openssh security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:6461 Important: openssh security update AlmaLinux Security Advisories · Oct 29, 2026
- ICSA-26-295-11 Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP CISA ICS & IT advisories · Oct 22, 2026
- RHSA-2026:5475 Red Hat Security Advisory: Red Hat Hardened Images RPM Release Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:9732 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:9415 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:7107 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:6462 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:6463 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:6461 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:15893 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:15891 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:14924 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:13750 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:10714 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- SSA-019113 SSA-019113: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.6 Siemens ProductCERT · Oct 13, 2026
- WID-SEC-2026-0716 OpenSSH GSSAPI delta: Schwachstelle ermöglicht nicht spezifizierten Angriff BSI CERT-Bund (WID) · Aug 31, 2026
- SUSE-SU-2026:23249-1 Security update for openssh SUSE / openSUSE Security Updates · Aug 27, 2026
- ICSA-26-209-04 Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP CISA ICS & IT advisories · Jul 28, 2026
- WID-SEC-2026-1730 Xerox FreeFlow Print Server: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Jul 16, 2026
- SUSE-SU-2026:22352-1 Security update for openssh SUSE / openSUSE Security Updates · Jul 2, 2026
- openSUSE-SU-2026:21044-1 Security update for openssh SUSE / openSUSE Security Updates · Jun 30, 2026
- SUSE-SU-2026:22268-1 Security update for openssh SUSE / openSUSE Security Updates · Jun 30, 2026
- SUSE-SU-2026:2430-1 Security update for openssh8.4 SUSE / openSUSE Security Updates · Jun 18, 2026
- SUSE-SU-2026:2395-1 Security update for openssh SUSE / openSUSE Security Updates · Jun 16, 2026
- SUSE-SU-2026:22067-1 Security update for openssh SUSE / openSUSE Security Updates · Jun 13, 2026
- SUSE-SU-2026:2371-1 Security update for openssh SUSE / openSUSE Security Updates · Jun 12, 2026
- SUSE-SU-2026:2375-1 Security update for openssh SUSE / openSUSE Security Updates · Jun 12, 2026
- openSUSE-SU-2026:10937-1 openssh-10.3p1-6.1 on GA media SUSE / openSUSE Security Updates · Jun 3, 2026
- ALAS2023-2026-1745 Moderate: openssh security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · May 26, 2026
- RLSA-2026:6462 Important: openssh security update Rocky Linux Security Advisories · May 21, 2026
- RLSA-2026:6463 Important: openssh security update Rocky Linux Security Advisories · May 21, 2026
- RLSA-2026:6461 Important: openssh security update Rocky Linux Security Advisories · Apr 9, 2026
- ELSA-2026-6462 Important: openssh security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Apr 3, 2026
- ELSA-2026-6463 Important: openssh security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Apr 2, 2026
- ELSA-2026-6461 Important: openssh security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Apr 2, 2026