CVE-2025-26465

MEDIUM

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.

CVSS v3.1 Score

6.8
MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Published: 2/18/2025Modified: 7/14/2026

Related Intelligence (0)

No articles currently reference this CVE.

References (28)

https://access.redhat.com/errata/RHSA-2025:16823https://access.redhat.com/errata/RHSA-2025:3837https://access.redhat.com/errata/RHSA-2025:6993https://access.redhat.com/errata/RHSA-2025:8385https://access.redhat.com/security/cve/CVE-2025-26465Third Party Advisoryhttps://access.redhat.com/solutions/7109879https://bugzilla.redhat.com/show_bug.cgi?id=2344780Issue TrackingThird Party Advisoryhttps://seclists.org/oss-sec/2025/q1/144Mailing ListThird Party Advisoryhttp://seclists.org/fulldisclosure/2025/Feb/18http://seclists.org/fulldisclosure/2025/May/7http://seclists.org/fulldisclosure/2025/May/8https://blog.qualys.com/vulnerabilities-threat-research/2025/02/18/qualys-tru-discovers-two-vulnerabilities-in-openssh-cve-2025-26465-cve-2025-26466Third Party Advisoryhttps://bugzilla.suse.com/show_bug.cgi?id=1237040Issue Trackinghttps://ftp.openbsd.org/pub/OpenBSD/patches/7.6/common/008_ssh.patch.sigPatchhttps://lists.debian.org/debian-lts-announce/2025/02/msg00020.htmlThird Party Advisoryhttps://lists.mindrot.org/pipermail/openssh-unix-announce/2025-February/000161.htmlThird Party Advisoryhttps://security-tracker.debian.org/tracker/CVE-2025-26465Third Party Advisoryhttps://security.netapp.com/advisory/ntap-20250228-0003/Third Party Advisoryhttps://ubuntu.com/security/CVE-2025-26465Third Party Advisoryhttps://www.openssh.com/releasenotes.html#9.9p2Release Noteshttps://www.openwall.com/lists/oss-security/2025/02/18/1Mailing ListThird Party Advisoryhttps://www.openwall.com/lists/oss-security/2025/02/18/4Mailing ListThird Party Advisoryhttps://www.theregister.com/2025/02/18/openssh_vulnerabilities_mitm_dos/Press/Media Coveragehttps://www.vicarius.io/vsociety/posts/cve-2025-26465-detect-vulnerable-opensshThird Party Advisoryhttps://www.vicarius.io/vsociety/posts/cve-2025-26465-mitigate-vulnerable-opensshMitigationThird Party Advisoryhttps://cert-portal.siemens.com/productcert/html/ssa-082556.htmlhttps://cert-portal.siemens.com/productcert/html/ssa-585531.htmlhttps://seclists.org/oss-sec/2025/q1/144Mailing ListThird Party Advisory