CVE-2025-26465Openssh: machine-in-the-middle attack if verifyhostkeydns is enabled
Updated under an hour ago ()
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It affects Red Hat Enterprise Linux 8 and 7 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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
- 6.8 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
- Weakness (CWE)
- CWE-390
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- redhat
- NVD analysis
- Not yet received
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 15, 2026
Affected products
Red Hat Red Hat Enterprise Linux 8 redhat:enterprise_linux | from 0:8.0p1-26.el8_10 not affected | CNA record |
Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support redhat:rhel_eus | from 0:8.7p1-38.el9_4.5 not affected | CNA record |
Red Hat Red Hat Discovery 1.14 redhat:discovery | from 1.14.3-1748529279 not affected | CNA record |
Red Hat Red Hat OpenShift Container Platform 4 redhat:openshift | 4 | CNA record |
Siemens SIDIS Secured SmartPlug siemens:sidis_secured_smartplug (from the name) | before V7.26.0310 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.5 | CISA ADP |
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name) | from V3.1.5 | CISA ADP |
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name) | from V3.1.5 | CISA ADP |
References
- https://access.redhat.com/errata/RHSA-2025:16823vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2025:3837vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2025:6993vendor-advisory, x-refsource-redhat
- https://access.redhat.com/errata/RHSA-2025:8385vendor-advisory, x-refsource-redhat
- https://access.redhat.com/security/cve/CVE-2025-26465vdb-entry, x-refsource-redhat
- https://access.redhat.com/solutions/7109879
- https://bugzilla.redhat.com/show_bug.cgi?id=2344780issue-tracking, x-refsource-redhat
- https://seclists.org/oss-sec/2025/q1/144
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.