CVE-2025-26466

5.9 MEDIUM
Published: February 28, 2025 Modified: November 03, 2025

Description

A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://access.redhat.com/security/cve/CVE-2025-26466
Source: secalert@redhat.com
Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2345043
Source: secalert@redhat.com
Issue Tracking
https://seclists.org/oss-sec/2025/q1/144
Source: secalert@redhat.com
https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt
Source: secalert@redhat.com
Third Party Advisory
http://seclists.org/fulldisclosure/2025/Feb/18
Source: af854a3a-2127-422b-91ae-364da2661108
http://seclists.org/fulldisclosure/2025/May/7
Source: af854a3a-2127-422b-91ae-364da2661108
http://seclists.org/fulldisclosure/2025/May/8
Source: af854a3a-2127-422b-91ae-364da2661108
https://bugzilla.suse.com/show_bug.cgi?id=1237041
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2025-26466
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://security.netapp.com/advisory/ntap-20250228-0002/
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://ubuntu.com/security/CVE-2025-26466
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://www.openwall.com/lists/oss-security/2025/02/18/1
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List Third Party Advisory
https://www.openwall.com/lists/oss-security/2025/02/18/4
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List Third Party Advisory
https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Third Party Advisory

14 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.9 / 10.0
EPSS (Exploit Probability)
46.7%
98th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

canonical openbsd debian