Medium severity6.8NVD Advisory· Published Feb 18, 2025· Updated May 12, 2026
CVE-2025-26465
CVE-2025-26465
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.
Affected products
1Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
26- ftp.openbsd.org/pub/OpenBSD/patches/7.6/common/008_ssh.patch.signvdPatch
- access.redhat.com/security/cve/CVE-2025-26465nvdThird Party Advisory
- blog.qualys.com/vulnerabilities-threat-research/2025/02/18/qualys-tru-discovers-two-vulnerabilities-in-openssh-cve-2025-26465-cve-2025-26466nvdThird Party Advisory
- bugzilla.redhat.com/show_bug.cginvdIssue TrackingThird Party Advisory
- lists.debian.org/debian-lts-announce/2025/02/msg00020.htmlnvdThird Party Advisory
- lists.mindrot.org/pipermail/openssh-unix-announce/2025-February/000161.htmlnvdThird Party Advisory
- seclists.org/oss-sec/2025/q1/144nvdMailing ListThird Party Advisory
- security-tracker.debian.org/tracker/CVE-2025-26465nvdThird Party Advisory
- security.netapp.com/advisory/ntap-20250228-0003/nvdThird Party Advisory
- ubuntu.com/security/CVE-2025-26465nvdThird Party Advisory
- www.openwall.com/lists/oss-security/2025/02/18/1nvdMailing ListThird Party Advisory
- www.openwall.com/lists/oss-security/2025/02/18/4nvdMailing ListThird Party Advisory
- www.vicarius.io/vsociety/posts/cve-2025-26465-detect-vulnerable-opensshnvdThird Party Advisory
- www.vicarius.io/vsociety/posts/cve-2025-26465-mitigate-vulnerable-opensshnvdMitigationThird Party Advisory
- bugzilla.suse.com/show_bug.cginvdIssue Tracking
- www.openssh.com/releasenotes.htmlnvdRelease Notes
- www.theregister.com/2025/02/18/openssh_vulnerabilities_mitm_dos/nvdPress/Media Coverage
- seclists.org/fulldisclosure/2025/Feb/18nvd
- seclists.org/fulldisclosure/2025/May/7nvd
- seclists.org/fulldisclosure/2025/May/8nvd
- access.redhat.com/errata/RHSA-2025:16823nvd
- access.redhat.com/errata/RHSA-2025:3837nvd
- access.redhat.com/errata/RHSA-2025:6993nvd
- access.redhat.com/errata/RHSA-2025:8385nvd
- access.redhat.com/solutions/7109879nvd
- cert-portal.siemens.com/productcert/html/ssa-082556.htmlnvd
News mentions
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