Ubuntu update for openssh

1) Man-in-the-Middle (MitM) attack

EUVDB-ID: #VU104035

Risk: Medium

CVSSv4.0: 2.1 [CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-26465

CWE-ID: CWE-300 - Channel Accessible by Non-Endpoint ('Man-in-the-Middle')

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to incorrect processing of user-supplied data in ssh(1). A remote attacker can perform server impersonation when VerifyHostKeyDNS enabled.

Mitigation

Update the affected package openssh to the latest version.

Vulnerable software versions

Ubuntu: 16.04 - 18.04

openssh-client (Ubuntu package): before Ubuntu Pro

openssh-server (Ubuntu package): before Ubuntu Pro (Infra-only)

CPE2.3

• cpe:2.3:o:canonical:ubuntu:16.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:18.04:*:*:*:*:*:*:*
• cpe:2.3:a:canonical:openssh-client_ubuntu_package:*:*:*:*:*:ubuntu:*:*
• cpe:2.3:a:canonical:openssh-server_ubuntu_package:*:*:*:*:*:ubuntu:*:*

External links

https://ubuntu.com/security/notices/USN-7270-2

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.