CVE-2025-26466 Information

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.

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Reference

https://access.redhat.com/security/cve/CVE-2025-26466 https://bugzilla.redhat.com/show_bug.cgi?id=2345043 https://security.netapp.com/advisory/ntap-20250228-0002/ https://www.qualys.com/2025/02/18/openssh-mitm-dos.txt

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

5.9