CVE-2025-26465
MEDIUM EPSS 93.4%
Published Feb 18, 20251y ago · Modified Jun 17, 20261w ago
6.8 CVSS 3.1
Published Feb 18, 2025 1y ago
Last Modified Jun 17, 2026 1w ago
Description
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 Details
Base Score
Exploitability
Impact
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction Required
Scope Unchanged
Confidentiality High
Integrity High
Availability None
Threat Intelligence
EPSS Exploit Probability
93.4% percentile
Exploit & Patch Status
No Known Exploit
Patch Available
Weaknesses 1
CWE-390
Affected Products 10
References 26
- seclists.org http://seclists.org/fulldisclosure/2025/Feb/18
- seclists.org http://seclists.org/fulldisclosure/2025/May/7
- seclists.org http://seclists.org/fulldisclosure/2025/May/8
- access.redhat.com https://access.redhat.com/errata/RHSA-2025:16823
- access.redhat.com https://access.redhat.com/errata/RHSA-2025:3837
- access.redhat.com https://access.redhat.com/errata/RHSA-2025:6993
- access.redhat.com https://access.redhat.com/errata/RHSA-2025:8385
- access.redhat.com https://access.redhat.com/security/cve/CVE-2025-26465
- access.redhat.com https://access.redhat.com/solutions/7109879
- blog.qualys.com https://blog.qualys.com/vulnerabilities-threat-research/2025/02/18/qualys-tru-discovers-two-vulnerabilities-in-openssh-cve-2025-26465-cve-2025-26466
- bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=2344780
- bugzilla.suse.com https://bugzilla.suse.com/show_bug.cgi?id=1237040
- cert-portal.siemens.com https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- ftp.openbsd.org https://ftp.openbsd.org/pub/OpenBSD/patches/7.6/common/008_ssh.patch.sig
- lists.debian.org https://lists.debian.org/debian-lts-announce/2025/02/msg00020.html
- lists.mindrot.org https://lists.mindrot.org/pipermail/openssh-unix-announce/2025-February/000161.html
- seclists.org https://seclists.org/oss-sec/2025/q1/144
- security-tracker.debian.org https://security-tracker.debian.org/tracker/CVE-2025-26465
- security.netapp.com https://security.netapp.com/advisory/ntap-20250228-0003/
- ubuntu.com https://ubuntu.com/security/CVE-2025-26465
- openssh.com https://www.openssh.com/releasenotes.html#9.9p2
- openwall.com https://www.openwall.com/lists/oss-security/2025/02/18/1
- openwall.com https://www.openwall.com/lists/oss-security/2025/02/18/4
- theregister.com https://www.theregister.com/2025/02/18/openssh_vulnerabilities_mitm_dos/
- vicarius.io https://www.vicarius.io/vsociety/posts/cve-2025-26465-detect-vulnerable-openssh
- vicarius.io https://www.vicarius.io/vsociety/posts/cve-2025-26465-mitigate-vulnerable-openssh
Remediation
- ftp.openbsd.org https://ftp.openbsd.org/pub/OpenBSD/patches/7.6/common/008_ssh.patch.sig