CVE-2025-26465
Fixed in a distro release EPSS 8%CVSS 6.8
A vulnerability was found in OpenSSH when the VerifyHostKeyDNS option is enabled. A machine-in-the-middle attack can be performed by a malicious machine impersonating a legit server. This issue occurs due to how OpenSSH mishandles error codes in specific conditions when verifying the host key. For an attack to be considered successful, the attacker needs to manage to exhaust the client's memory resource first, turning the attack complexity high.
Products: Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat Enterprise Linux 9.4 Extended Update Support, Red Hat Discovery 1.14, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat OpenShift Container Platform 4, Siemens SIDIS Secured SmartPlug, Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP, Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| AlmaLinux 8 | openssh | 8.0p1-26.el8_10 |
| AlmaLinux 8 | openssh-askpass | 8.0p1-26.el8_10 |
| AlmaLinux 8 | openssh-cavs | 8.0p1-26.el8_10 |
| AlmaLinux 8 | openssh-clients | 8.0p1-26.el8_10 |
| AlmaLinux 8 | openssh-keycat | 8.0p1-26.el8_10 |
| AlmaLinux 8 | openssh-ldap | 8.0p1-26.el8_10 |
| AlmaLinux 8 | openssh-server | 8.0p1-26.el8_10 |
| AlmaLinux 8 | pam_ssh_agent_auth | 0.10.3-7.26.el8_10 |
| AlmaLinux 9 | openssh | 8.7p1-45.el9 |
| AlmaLinux 9 | openssh-askpass | 8.7p1-45.el9 |
| AlmaLinux 9 | openssh-clients | 8.7p1-45.el9 |
| AlmaLinux 9 | openssh-keycat | 8.7p1-45.el9 |
| AlmaLinux 9 | openssh-server | 8.7p1-45.el9 |
| AlmaLinux 9 | pam_ssh_agent_auth | 0.10.4-5.45.el9 |
| Alpine 3.18 | openssh | 9.3_p2-r3 |
| Alpine 3.19 | openssh | 9.6_p1-r2 |
| Alpine 3.20 | openssh | 9.7_p1-r5 |
| Alpine 3.21 | openssh | 9.9_p2-r0 |
| Alpine 3.22 | openssh | 9.9_p2-r0 |
| Alpine 3.23 | openssh | 9.9_p2-r0 |
| Alpine 3.24 | openssh | 9.9_p2-r0 |
| Debian 11 | openssh | 1:8.4p1-5+deb11u4 |
| Debian 12 | openssh | 1:9.2p1-2+deb12u5 |
| Debian 13 | openssh | 1:9.9p2-1 |
| Debian 14 | openssh | 1:9.9p2-1 |
| Red Hat Enterprise Linux 8 | openssh | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-askpass | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-askpass-debuginfo | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-cavs | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-cavs-debuginfo | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-clients | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-clients-debuginfo | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-debuginfo | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-debugsource | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-keycat | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-keycat-debuginfo | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-ldap | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-ldap-debuginfo | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-server | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | openssh-server-debuginfo | 0:8.0p1-26.el8_10 |
| Red Hat Enterprise Linux 8 | pam_ssh_agent_auth | 0:0.10.3-7.26.el8_10 |
| Red Hat Enterprise Linux 8 | pam_ssh_agent_auth-debuginfo | 0:0.10.3-7.26.el8_10 |
| Red Hat Enterprise Linux 9 | openssh | 0:8.7p1-45.el9 |
| Red Hat Enterprise Linux 9 | openssh-askpass | 0:8.7p1-45.el9 |
| Red Hat Enterprise Linux 9 | openssh-askpass-debuginfo | 0:8.7p1-45.el9 |
| Red Hat Enterprise Linux 9 | openssh-clients | 0:8.7p1-45.el9 |
| Red Hat Enterprise Linux 9 | openssh-clients-debuginfo | 0:8.7p1-45.el9 |
| Red Hat Enterprise Linux 9 | openssh-debuginfo | 0:8.7p1-45.el9 |
| Red Hat Enterprise Linux 9 | openssh-debugsource | 0:8.7p1-45.el9 |
| Red Hat Enterprise Linux 9 | openssh-keycat | 0:8.7p1-45.el9 |
| Red Hat Enterprise Linux 9 | openssh-keycat-debuginfo | 0:8.7p1-45.el9 |
| Red Hat Enterprise Linux 9 | openssh-server | 0:8.7p1-45.el9 |
| Red Hat Enterprise Linux 9 | openssh-server-debuginfo | 0:8.7p1-45.el9 |
| Red Hat Enterprise Linux 9 | openssh-sk-dummy-debuginfo | 0:8.7p1-45.el9 |
| Red Hat Enterprise Linux 9 | pam_ssh_agent_auth | 0:0.10.4-5.45.el9 |
| Red Hat Enterprise Linux 9 | pam_ssh_agent_auth-debuginfo | 0:0.10.4-5.45.el9 |
| Red Hat rhel eus 9.4 | openssh | 0:8.7p1-38.el9_4.5 |
| Red Hat rhel eus 9.4 | openssh-askpass | 0:8.7p1-38.el9_4.5 |
| Red Hat rhel eus 9.4 | openssh-askpass-debuginfo | 0:8.7p1-38.el9_4.5 |
| Red Hat rhel eus 9.4 | openssh-clients | 0:8.7p1-38.el9_4.5 |
| Red Hat rhel eus 9.4 | openssh-clients-debuginfo | 0:8.7p1-38.el9_4.5 |
| Red Hat rhel eus 9.4 | openssh-debuginfo | 0:8.7p1-38.el9_4.5 |
| Red Hat rhel eus 9.4 | openssh-debugsource | 0:8.7p1-38.el9_4.5 |
| Red Hat rhel eus 9.4 | openssh-keycat | 0:8.7p1-38.el9_4.5 |
| Red Hat rhel eus 9.4 | openssh-keycat-debuginfo | 0:8.7p1-38.el9_4.5 |
| Red Hat rhel eus 9.4 | openssh-server | 0:8.7p1-38.el9_4.5 |
| Red Hat rhel eus 9.4 | openssh-server-debuginfo | 0:8.7p1-38.el9_4.5 |
| Red Hat rhel eus 9.4 | openssh-sk-dummy-debuginfo | 0:8.7p1-38.el9_4.5 |
| Red Hat rhel eus 9.4 | pam_ssh_agent_auth | 0:0.10.4-5.38.el9_4.5 |
| Red Hat rhel eus 9.4 | pam_ssh_agent_auth-debuginfo | 0:0.10.4-5.38.el9_4.5 |
| Rocky Linux 8 | openssh | 0:8.0p1-26.el8_10 |
| Rocky Linux 9 | openssh | 0:8.7p1-45.el9 |
| SUSE Enterprise Storage 7.1 | openssh | 8.4p1-150300.3.42.1 |
| SUSE Enterprise Storage 7.1 | openssh-askpass-gnome | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | openssh-askpass-gnome | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | openssh-askpass-gnome | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | openssh-askpass-gnome | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | openssh-askpass-gnome | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | openssh-askpass-gnome | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Micro 5.1 | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Micro 5.2 | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Micro 5.3 | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Micro 5.4 | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Micro 5.5 | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | openssh | 9.6p1-150600.6.15.2 |
| SUSE Linux Enterprise Module for Desktop Applications 15 SP6 | openssh-askpass-gnome | 9.6p1-150600.6.15.1 |
| SUSE Linux Enterprise Server 12 SP5-LTSS | openssh | 7.2p2-81.26.1 |
| SUSE Linux Enterprise Server 12 SP5-LTSS | openssh-askpass-gnome | 7.2p2-81.26.1 |
| SUSE Linux Enterprise Server 12 SP5-LTSS | openssh8.4 | 8.4p1-8.16.1 |
| SUSE Linux Enterprise Server 15 SP3-LTSS | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Server 15 SP3-LTSS | openssh-askpass-gnome | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Server 15 SP4-LTSS | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Server 15 SP4-LTSS | openssh-askpass-gnome | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Server 15 SP5-LTSS | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Server 15 SP5-LTSS | openssh-askpass-gnome | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | openssh | 7.2p2-81.26.1 |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | openssh-askpass-gnome | 7.2p2-81.26.1 |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | openssh8.4 | 8.4p1-8.16.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | openssh-askpass-gnome | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | openssh-askpass-gnome | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | openssh | 8.4p1-150300.3.42.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | openssh-askpass-gnome | 8.4p1-150300.3.42.1 |
| SUSE Linux Micro 6.0 | openssh | 9.6p1-3.1 |
| SUSE Linux Micro 6.1 | openssh | 9.6p1-slfo.1.1_2.1 |
| SUSE Manager Proxy 4.3 | openssh | 8.4p1-150300.3.42.1 |
| SUSE Manager Server 4.3 | openssh | 8.4p1-150300.3.42.1 |
| Ubuntu 18.04 LTS | openssh-ssh1 | no fix |
| Ubuntu 20.04 LTS | openssh | 1:8.2p1-4ubuntu0.12 |
| Ubuntu 20.04 LTS | openssh-ssh1 | no fix |
| Ubuntu 22.04 LTS | openssh | 1:8.9p1-3ubuntu0.11 |
| Ubuntu 22.04 LTS | openssh-ssh1 | no fix |
| Ubuntu 24.04 LTS | openssh | 1:9.6p1-3ubuntu13.8 |
| Ubuntu 24.04 LTS | openssh-ssh1 | no fix |
| Ubuntu 25.10 | openssh-ssh1 | no fix |
| Ubuntu 26.04 LTS | openssh-ssh1 | no fix |
| Ubuntu 26.10 | openssh-ssh1 | no fix |
| Ubuntu Pro 16.04 LTS | openssh | 1:7.2p2-4ubuntu2.10+esm7 |
| Ubuntu Pro 18.04 LTS | openssh | 1:7.6p1-4ubuntu0.7+esm4 |
| Ubuntu Pro FIPS-preview 22.04 LTS | openssh | no fix |
| Ubuntu Pro FIPS-updates 16.04 LTS | openssh | 1:7.2p2-4ubuntu2.fips.2.10.7 |
| Ubuntu Pro FIPS-updates 18.04 LTS | openssh | 1:7.9p1-10~ubuntu18.04.fips.0.10 |
| Ubuntu Pro FIPS-updates 20.04 LTS | openssh | 1:8.2p1-4ubuntu0.fips.0.12 |
| Ubuntu Pro FIPS-updates 22.04 LTS | openssh | 1:8.9p1-3ubuntu0.11+Fips1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | openssh | 1:9.6p1-3ubuntu13.12+Fips1 |
| Ubuntu Pro FIPS 16.04 LTS | openssh | no fix |
| Ubuntu Pro FIPS 18.04 LTS | openssh | no fix |
| Ubuntu Pro FIPS 20.04 LTS | openssh | no fix |
| openSUSE Leap 15.6 | openssh | 9.6p1-150600.6.15.2 |
| openSUSE Leap 15.6 | openssh-askpass-gnome | 9.6p1-150600.6.15.1 |
| openSUSE Tumbleweed | openssh | 9.9p2-1.1 |