Description
ssh in OpenSSH before 10.4 can have a use-after-free when a server changes its host key during a key re-exchange. (This outcome occurs only on the client side.)
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| OpenBSD | OpenSSH | < 10.4 | 10.4 |
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 | 1:10.4p1-1 | — |
| Debian 13 | openssh | No fix yet | — |
| Debian 12 | openssh | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | openssh-ssh1 | No fix yet | — |
| Ubuntu 26.04 LTS | openssh | 1:10.2p1-2ubuntu3.4 | USN-8533-1 |
| Ubuntu 26.04 LTS | openssh-ssh1 | No fix yet | — |
| Ubuntu 25.10 | openssh +1 | No fix yet | — |
| Ubuntu 24.04 LTS | openssh | 1:9.6p1-3ubuntu13.18 | USN-8533-1 |
| Ubuntu 24.04 LTS | openssh-ssh1 | No fix yet | — |
| Ubuntu 22.04 LTS | openssh | 1:8.9p1-3ubuntu0.16 | USN-8533-1 |
| Ubuntu 22.04 LTS | openssh-ssh1 | No fix yet | — |
Show 11 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 | 1:9.6p1-3ubuntu13.18+Fips1 | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | openssh | 1:8.9p1-3ubuntu0.16+Fips3 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | openssh | No fix yet | — |
| 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 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | openssh +5 | 9.9p1-25.el10_2 | RHSA-2026:47757 |
| RHEL 9 | openssh +4 | 9.9p1-9.el9_8 | RHSA-2026:47756 |
| RHEL 9 | pam_ssh_agent_auth | 0.10.4-7.9.el9_8 | RHSA-2026:47756 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | openssh +5 | 9.9p1-7.el10_0.4 | RHSA-2026:65900 |
| RHEL 9.6 EUS | openssh +4 | 8.7p1-45.el9_6.4 | RHSA-2026:66410 |
| RHEL 9.6 EUS | pam_ssh_agent_auth | 0.10.4-5.45.el9_6.4 | RHSA-2026:66410 |
| RHEL 9.4 E4S | openssh-server +1 | 8.7p1-38.el9_4.10 | RHSA-2026:76993 |
| Red Hat Hardened Images 1 | openssh +6 | 10.4p1-1.hum1 | RHSA-2026:37382 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | openssh +5 | 9.9p1-25.el10_2.alma.1 | ALSA-2026:47757 |
| AlmaLinux 9 | openssh +4 | 9.9p1-9.el9_8.alma.1 | ALSA-2026:47756 |
| AlmaLinux 9 | pam_ssh_agent_auth | 0.10.4-7.9.el9_8.alma.1 | ALSA-2026:47756 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | openssh | 9.9p1-25.el10_2.rocky.0.1 | RLSA-2026:47757 |
| Rocky Linux 9 | openssh | 9.9p1-9.el9_8.rocky.0.1 | RLSA-2026:47756 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | openssh +1 | 9.6p1-150600.6.49.1 | SUSE-SU-2026:3605-1 |
| SLES 15 SP6 | openssh +1 | 9.6p1-150600.6.49.1 | SUSE-SU-2026:3605-1 |
| SLES 12 SP5 | openssh8.4 | 8.4p1-8.30.1 | SUSE-SU-2026:4907-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | openssh +1 | 9.6p1-150600.6.49.1 | SUSE-SU-2026:3605-1 |
| SLE Micro 6.2 | openssh | 10.0p2-160000.7.1 | SUSE-SU-2026:22978-1 |
| SLE Micro 6.1 | openssh | 9.6p1-slfo.1.1_7.1 | SUSE-SU-2026:24382-1 |
| SLE Micro 6.0 | openssh | 9.6p1-159998.2.1 | SUSE-SU-2026:24478-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | openssh +1 | 10.0p2-160000.7.1 | openSUSE-SU-2026:21477-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | openssh | 10.3_p1-r1 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | openssh +4 | 9.9p1-10.amzn2023.0.1 | ALAS2023-2026-2031 |
| Amazon Linux 2023 | pam_ssh_agent_auth | 0.10.4-9.10.amzn2023.0.1 | ALAS2023-2026-2031 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | openssh | 9.8p1-9 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | openssh +5 | 9.9p1-25.0.1.el10_2 | ELSA-2026-47757 |
| Oracle Linux 9 | openssh +4 | 9.9p1-9.0.1.el9_8 | ELSA-2026-47756 |
| Oracle Linux 9 | pam_ssh_agent_auth | 0.10.4-7.9.0.1.el9_8 | ELSA-2026-47756 |
Advisories 24
- WID-SEC-2026-2221 OpenSSH: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 11, 2026
- SUSE-SU-2026:24478-1 Security update for openssh SUSE / openSUSE Security Updates · Nov 4, 2026
- ALSA-2026:47756 Important: openssh security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:47757 Important: openssh security update AlmaLinux Security Advisories · Oct 29, 2026
- SUSE-SU-2026:24382-1 Security update for openssh SUSE / openSUSE Security Updates · Oct 27, 2026
- SUSE-SU-2026:4907-1 Security update for openssh8.4 SUSE / openSUSE Security Updates · Oct 26, 2026
- RHSA-2026:37382 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- RHSA-2026:76993 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:47757 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:47756 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:66410 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 14, 2026
- RHSA-2026:65900 Red Hat Security Advisory: openssh security update Red Hat Security Advisories (RHSA) · Oct 14, 2026
- WID-SEC-2026-2858 IBM AIX und VIOS: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 4, 2026
- WID-SEC-2026-3038 Meinberg LANTIME: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 26, 2026
- NCSC-2026-0321 Meerdere kwetsbaarheden verholpen in IBM AIX en IBM PowerVM VIOS NCSC-NL (Netherlands) · Aug 21, 2026
- SUSE-SU-2026:3605-1 Security update for openssh SUSE / openSUSE Security Updates · Aug 14, 2026
- ELSA-2026-47756 Important: openssh security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Aug 6, 2026
- SUSE-SU-2026:22978-1 Security update for openssh SUSE / openSUSE Security Updates · Aug 4, 2026
- ALAS2023-2026-2031 Moderate: openssh security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 4, 2026
- openSUSE-SU-2026:21477-1 Security update for openssh SUSE / openSUSE Security Updates · Jul 31, 2026
- RLSA-2026:47756 Important: openssh security update Rocky Linux Security Advisories · Jul 30, 2026
- RLSA-2026:47757 Important: openssh security update Rocky Linux Security Advisories · Jul 30, 2026
- ELSA-2026-47757 Important: openssh security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 30, 2026
- USN-8533-1 openssh vulnerabilities Ubuntu Security Notices (USN) · Jul 13, 2026