CVE-2025-26465

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.
References
Link Resource
https://access.redhat.com/errata/RHSA-2025:16823
https://access.redhat.com/errata/RHSA-2025:3837
https://access.redhat.com/errata/RHSA-2025:6993
https://access.redhat.com/errata/RHSA-2025:8385
https://access.redhat.com/security/cve/CVE-2025-26465 Third Party Advisory
https://access.redhat.com/solutions/7109879
https://bugzilla.redhat.com/show_bug.cgi?id=2344780 Issue Tracking Third Party Advisory
https://seclists.org/oss-sec/2025/q1/144 Mailing List Third Party Advisory
http://seclists.org/fulldisclosure/2025/Feb/18
http://seclists.org/fulldisclosure/2025/May/7
http://seclists.org/fulldisclosure/2025/May/8
https://blog.qualys.com/vulnerabilities-threat-research/2025/02/18/qualys-tru-discovers-two-vulnerabilities-in-openssh-cve-2025-26465-cve-2025-26466 Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=1237040 Issue Tracking
https://ftp.openbsd.org/pub/OpenBSD/patches/7.6/common/008_ssh.patch.sig Patch
https://lists.debian.org/debian-lts-announce/2025/02/msg00020.html Third Party Advisory
https://lists.mindrot.org/pipermail/openssh-unix-announce/2025-February/000161.html Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2025-26465 Third Party Advisory
https://security.netapp.com/advisory/ntap-20250228-0003/ Third Party Advisory
https://ubuntu.com/security/CVE-2025-26465 Third Party Advisory
https://www.openssh.com/releasenotes.html#9.9p2 Release Notes
https://www.openwall.com/lists/oss-security/2025/02/18/1 Mailing List Third Party Advisory
https://www.openwall.com/lists/oss-security/2025/02/18/4 Mailing List Third Party Advisory
https://www.theregister.com/2025/02/18/openssh_vulnerabilities_mitm_dos/ Press/Media Coverage
https://www.vicarius.io/vsociety/posts/cve-2025-26465-detect-vulnerable-openssh Third Party Advisory
https://www.vicarius.io/vsociety/posts/cve-2025-26465-mitigate-vulnerable-openssh Mitigation Third Party Advisory
https://seclists.org/oss-sec/2025/q1/144 Mailing List Third Party Advisory
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:openbsd:openssh:*:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:6.8:p1:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:9.9:-:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:9.9:p1:*:*:*:*:*:*

Configuration 2 (hide)

OR cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:*
cpe:2.3:a:netapp:ontap:9:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*

History

03 Nov 2025, 22:18

Type Values Removed Values Added
References
  • () http://seclists.org/fulldisclosure/2025/Feb/18 -
  • () http://seclists.org/fulldisclosure/2025/May/7 -
  • () http://seclists.org/fulldisclosure/2025/May/8 -

Information

Published : 2025-02-18 19:15

Updated : 2025-11-03 22:18


NVD link : CVE-2025-26465

Mitre link : CVE-2025-26465

CVE.ORG link : CVE-2025-26465


JSON object : View

Products Affected

redhat

  • enterprise_linux
  • openshift_container_platform

debian

  • debian_linux

netapp

  • ontap
  • active_iq_unified_manager

openbsd

  • openssh
CWE
CWE-390

Detection of Error Condition Without Action