6.8
MEDIUM
CVE-2025-26465
OpenSSH DNS Host Key Verification Denial of Service
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.

INFO

Published Date :

Feb. 18, 2025, 7:15 p.m.

Last Modified :

April 14, 2025, 11:15 a.m.

Source :

[email protected]

Remotely Exploitable :

Yes !

Impact Score :

5.2

Exploitability Score :

1.6
Public PoC/Exploit Available at Github

CVE-2025-26465 has a 7 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

Affected Products

The following products are affected by CVE-2025-26465 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Redhat enterprise_linux
2 Redhat openshift_container_platform
1 Netapp active_iq_unified_manager
2 Netapp ontap
1 Debian debian_linux
1 Openbsd openssh
: Total Affected Vendor : 4 | Products : 6
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-26465.

URL Resource
https://access.redhat.com/errata/RHSA-2025:3837
https://access.redhat.com/security/cve/CVE-2025-26465 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2344780 Issue Tracking Third Party Advisory
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

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Profile Photo
wooflock/nmap-airgapped-vulnscan

A small project for running vulners script functionality when no internet is available.

Python

Updated: 3 weeks, 5 days ago
0 stars 0 fork 0 watcher
Born at : March 21, 2025, 3:47 p.m. This repo has been linked 11 different CVEs too.
Profile Photo
Theshield-crack/wazuh-SIEM-with-ubuntu

None

Updated: 1 month, 3 weeks ago
0 stars 0 fork 0 watcher
Born at : Feb. 24, 2025, 2:19 p.m. This repo has been linked 3 different CVEs too.
Profile Photo
dolutech/patch-manual-CVE-2025-26465-e-CVE-2025-26466

Patch Manual para a correção das CVE-2025-26465-e-CVE-2025-26466, para sistemas sem update do OpenSSH

Shell

Updated: 1 month, 4 weeks ago
1 stars 0 fork 0 watcher
Born at : Feb. 21, 2025, 9:19 a.m. This repo has been linked 2 different CVEs too.
Profile Photo
rxerium/CVE-2025-26465

MitM attack allowing a malicious interloper to impersonate a legitimate server when a client attempts to connect to it

cyber-security ssh vulnerability

Updated: 1 month ago
2 stars 0 fork 0 watcher
Born at : Feb. 18, 2025, 4:53 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
M-e-e-n-a/crime_data_analysis

None

Python

Updated: 1 month, 4 weeks ago
0 stars 0 fork 0 watcher
Born at : Dec. 8, 2024, 7:05 a.m. This repo has been linked 1 different CVEs too.
Profile Photo
mosaicwang/myrpm

我的RPM库

Updated: 4 days, 16 hours ago
6 stars 0 fork 0 watcher
Born at : Nov. 9, 2024, 9:08 a.m. This repo has been linked 11 different CVEs too.
Profile Photo
nomi-sec/PoC-in-GitHub

📡 PoC auto collect from GitHub. ⚠️ Be careful Malware.

security cve exploit poc vulnerability

Updated: 5 days, 18 hours ago
6834 stars 1157 fork 1157 watcher
Born at : Dec. 8, 2019, 1:03 p.m. This repo has been linked 849 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-26465 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2025-26465 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    Apr. 14, 2025

    Action Type Old Value New Value
    Added Reference https://access.redhat.com/errata/RHSA-2025:3837
  • Initial Analysis by [email protected]

    Mar. 06, 2025

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
    Added CPE Configuration OR *cpe:2.3:a:openbsd:openssh:6.8:p1:*:*:*:*:*:* *cpe:2.3:a:openbsd:openssh:*:*:*:*:*:*:*:* versions from (including) 6.9 from (including) 9.8 *cpe:2.3:a:openbsd:openssh:9.9:-:*:*:*:*:*:* *cpe:2.3:a:openbsd:openssh:9.9:p1:*:*:*:*:*:*
    Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* *cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:* *cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:* *cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* *cpe:2.3:a:netapp:ontap:9:*:*:*:*:*:*:*
    Added Reference Type Red Hat, Inc.: https://access.redhat.com/security/cve/CVE-2025-26465 Types: Third Party Advisory
    Added Reference Type CVE: https://blog.qualys.com/vulnerabilities-threat-research/2025/02/18/qualys-tru-discovers-two-vulnerabilities-in-openssh-cve-2025-26465-cve-2025-26466 Types: Third Party Advisory
    Added Reference Type Red Hat, Inc.: https://bugzilla.redhat.com/show_bug.cgi?id=2344780 Types: Issue Tracking, Third Party Advisory
    Added Reference Type CVE: https://bugzilla.suse.com/show_bug.cgi?id=1237040 Types: Issue Tracking
    Added Reference Type CVE: https://ftp.openbsd.org/pub/OpenBSD/patches/7.6/common/008_ssh.patch.sig Types: Patch
    Added Reference Type CVE: https://lists.debian.org/debian-lts-announce/2025/02/msg00020.html Types: Third Party Advisory
    Added Reference Type CVE: https://lists.mindrot.org/pipermail/openssh-unix-announce/2025-February/000161.html Types: Third Party Advisory
    Added Reference Type CISA-ADP: https://seclists.org/oss-sec/2025/q1/144 Types: Mailing List, Third Party Advisory
    Added Reference Type CVE: https://security.netapp.com/advisory/ntap-20250228-0003/ Types: Third Party Advisory
    Added Reference Type CVE: https://security-tracker.debian.org/tracker/CVE-2025-26465 Types: Third Party Advisory
    Added Reference Type CVE: https://ubuntu.com/security/CVE-2025-26465 Types: Third Party Advisory
    Added Reference Type CVE: https://www.openssh.com/releasenotes.html#9.9p2 Types: Release Notes
    Added Reference Type CVE: https://www.openwall.com/lists/oss-security/2025/02/18/1 Types: Mailing List, Third Party Advisory
    Added Reference Type CVE: https://www.openwall.com/lists/oss-security/2025/02/18/4 Types: Mailing List, Third Party Advisory
    Added Reference Type CVE: https://www.theregister.com/2025/02/18/openssh_vulnerabilities_mitm_dos/ Types: Press/Media Coverage
    Added Reference Type CVE: https://www.vicarius.io/vsociety/posts/cve-2025-26465-detect-vulnerable-openssh Types: Third Party Advisory
    Added Reference Type CVE: https://www.vicarius.io/vsociety/posts/cve-2025-26465-mitigate-vulnerable-openssh Types: Mitigation, Third Party Advisory
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Mar. 03, 2025

    Action Type Old Value New Value
    Added Reference https://www.vicarius.io/vsociety/posts/cve-2025-26465-detect-vulnerable-openssh
    Added Reference https://www.vicarius.io/vsociety/posts/cve-2025-26465-mitigate-vulnerable-openssh
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Feb. 28, 2025

    Action Type Old Value New Value
    Added Reference https://security.netapp.com/advisory/ntap-20250228-0003/
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Feb. 19, 2025

    Action Type Old Value New Value
    Added Reference https://seclists.org/oss-sec/2025/q1/144
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Feb. 19, 2025

    Action Type Old Value New Value
    Added Reference https://blog.qualys.com/vulnerabilities-threat-research/2025/02/18/qualys-tru-discovers-two-vulnerabilities-in-openssh-cve-2025-26465-cve-2025-26466
    Added Reference https://bugzilla.suse.com/show_bug.cgi?id=1237040
    Added Reference https://ftp.openbsd.org/pub/OpenBSD/patches/7.6/common/008_ssh.patch.sig
    Added Reference https://lists.mindrot.org/pipermail/openssh-unix-announce/2025-February/000161.html
    Added Reference https://security-tracker.debian.org/tracker/CVE-2025-26465
    Added Reference https://ubuntu.com/security/CVE-2025-26465
    Added Reference https://www.openssh.com/releasenotes.html#9.9p2
    Added Reference https://www.openwall.com/lists/oss-security/2025/02/18/1
    Added Reference https://www.openwall.com/lists/oss-security/2025/02/18/4
    Added Reference https://www.theregister.com/2025/02/18/openssh_vulnerabilities_mitm_dos/
  • New CVE Received by [email protected]

    Feb. 18, 2025

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
    Added CWE CWE-390
    Added Reference https://access.redhat.com/security/cve/CVE-2025-26465
    Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2344780
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Feb. 18, 2025

    Action Type Old Value New Value
    Added Reference https://lists.debian.org/debian-lts-announce/2025/02/msg00020.html
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-26465 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-26465 weaknesses.

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
: