{"id":"CVE-2025-26465","details":"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.","modified":"2026-04-16T04:32:59.831545784Z","published":"2025-02-18T19:15:29.230Z","related":["ALSA-2025:16823","ALSA-2025:6993","SUSE-SU-2025:0585-1","SUSE-SU-2025:0605-1","SUSE-SU-2025:0659-1","SUSE-SU-2025:0744-1","SUSE-SU-2025:20160-1","SUSE-SU-2025:20226-1","openSUSE-SU-2025:14820-1"],"references":[{"type":"WEB","url":"http://seclists.org/fulldisclosure/2025/May/7"},{"type":"WEB","url":"http://seclists.org/fulldisclosure/2025/Feb/18"},{"type":"WEB","url":"https://www.theregister.com/2025/02/18/openssh_vulnerabilities_mitm_dos/"},{"type":"WEB","url":"http://seclists.org/fulldisclosure/2025/May/8"},{"type":"WEB","url":"https://access.redhat.com/solutions/7109879"},{"type":"ADVISORY","url":"https://lists.mindrot.org/pipermail/openssh-unix-announce/2025-February/000161.html"},{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2025-26465"},{"type":"ADVISORY","url":"https://www.openssh.com/releasenotes.html#9.9p2"},{"type":"ADVISORY","url":"https://www.openwall.com/lists/oss-security/2025/02/18/1"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2025:16823"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2025:3837"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2025:8385"},{"type":"ADVISORY","url":"https://blog.qualys.com/vulnerabilities-threat-research/2025/02/18/qualys-tru-discovers-two-vulnerabilities-in-openssh-cve-2025-26465-cve-2025-26466"},{"type":"ADVISORY","url":"https://ubuntu.com/security/CVE-2025-26465"},{"type":"ADVISORY","url":"https://www.openwall.com/lists/oss-security/2025/02/18/4"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2025:6993"},{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2025/02/msg00020.html"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20250228-0003/"},{"type":"ADVISORY","url":"https://www.vicarius.io/vsociety/posts/cve-2025-26465-detect-vulnerable-openssh"},{"type":"ADVISORY","url":"https://www.vicarius.io/vsociety/posts/cve-2025-26465-mitigate-vulnerable-openssh"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2025-26465"},{"type":"ADVISORY","url":"https://seclists.org/oss-sec/2025/q1/144"},{"type":"REPORT","url":"https://bugzilla.suse.com/show_bug.cgi?id=1237040"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2344780"},{"type":"FIX","url":"https://ftp.openbsd.org/pub/OpenBSD/patches/7.6/common/008_ssh.patch.sig"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/openssh/openssh-portable","events":[{"introduced":"7de4b03a6e4071d454b72927ffaf52949fa34545"},{"last_affected":"6849957945754e6551e515f41e8cf3937cda222d"},{"introduced":"0"},{"last_affected":"9f82e5a9042f2d872e98f48a876fcab3e25dd9bb"},{"introduced":"0"},{"last_affected":"53a80baaebda180f46e6e8571f3ff800e1f5c496"},{"introduced":"0"},{"last_affected":"485bab886137bbf8b7ec8df82bd66dc6e5654371"},{"introduced":"0"},{"last_affected":"94eb6858efecc1b4f02d8a6bd35e149f55c814c8"}],"database_specific":{"versions":[{"introduced":"6.9"},{"last_affected":"9.8"},{"introduced":"0"},{"last_affected":"6.8-p1"},{"introduced":"0"},{"last_affected":"9.9-p1"},{"introduced":"0"},{"last_affected":"4.0"},{"introduced":"0"},{"last_affected":"9.0"}]}}],"versions":["ABOUT_TO_ADD_INET_ATON","AFTER_FREEBSD_PAM_MERGE","AFTER_KRB5_GSSAPI_MERGE","BEFORE_FREEBSD_PAM_MERGE","BEFORE_KRB5_GSSAPI_MERGE","POST_KRB4_REMOVAL","PRE-REORDER","PRE_CYGWIN_MERGE","PRE_DAN_PATCH_MERGE","PRE_FIXPATHS_INTEGRATION","PRE_HPUX_INTEGRATION","PRE_IPV6","PRE_KRB4_REMOVAL","PRE_NEW_LOGIN_CODE","PRE_SW_KRBV","V_1_2PRE17","V_1_2_1_PRE18","V_1_2_1_PRE19","V_1_2_1_PRE20","V_1_2_1_PRE21","V_1_2_1_PRE22","V_1_2_1_PRE23","V_1_2_1_PRE24","V_1_2_1_PRE25","V_1_2_1_PRE26","V_1_2_1_PRE27","V_1_2_2","V_1_2_2_P1","V_1_2_2_PRE28","V_1_2_2_PRE29","V_1_2_3","V_1_2_3_PRE1","V_1_2_3_PRE2","V_1_2_3_PRE3","V_1_2_3_PRE4","V_1_2_3_PRE5","V_1_2_3_TEST1","V_1_2_3_TEST2","V_1_2_3_TEST3","V_1_2_PRE10","V_1_2_PRE11","V_1_2_PRE12","V_1_2_PRE13","V_1_2_PRE14","V_1_2_PRE15","V_1_2_PRE16","V_1_2_PRE4","V_1_2_PRE5","V_1_2_PRE6","V_1_2_PRE7","V_1_2_PRE8","V_1_2_PRE9","V_2_0_0_BETA1","V_2_0_0_BETA2","V_2_0_0_TEST1","V_2_1_0","V_2_1_0_P1","V_2_1_0_P2","V_2_1_0_P3","V_2_1_1_P1","V_2_1_1_P2","V_2_1_1_P3","V_2_1_1_P4","V_2_2_0_P1","V_2_3_0_P1","V_2_5_0_P1","V_2_5_1_P1","V_2_5_1_P2","V_2_5_2_P1","V_3_0_1_P1","V_3_0_P1","V_3_1_P1","V_3_2_2_P1","V_3_4_P1","V_3_6_1_P1","V_3_8_P1","V_3_9_P1","V_4_0_P1","V_4_2_P1","V_5_0_P1","V_5_1_P1","V_5_2_P1","V_5_5_P1","V_5_7_P1","V_6_0_P1","V_6_1_P1","V_6_2_P1","V_6_5_P1","V_6_6_P1","V_6_8_P1","V_6_9_P1","V_7_0_P1","V_7_1_P1","V_7_2_P1","V_7_3_P1","V_7_4_P1","V_7_5_P1","V_7_6_P1","V_7_7_P1","V_7_8_P1","V_7_9_P1","V_8_0_P1","V_8_1_P1","V_8_2_P1","V_8_4_P1","V_8_5_P1","V_8_6_P1","V_8_7_P1","V_8_8_P1","V_8_9_P1","V_9_0_P1","V_9_1_P1","V_9_2_P1","V_9_3_P1","V_9_5_P1","V_9_6_P1","V_9_7_P1","V_9_8_P1","V_9_9_P1"],"database_specific":{"source":"https://storage.googleapis.com/cve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