Summary
It was discovered that the OpenSSH client incorrectly handled the
non-default VerifyHostKeyDNS option. If that option were enabled, an
attacker could possibly impersonate a server by completely bypassing the
server identity check. (CVE-2025-26465)
It was discovered that OpenSSH incorrectly handled the transport-level ping
facility. A remote attacker could possibly use this issue to cause OpenSSH
clients and servers to consume resources, leading to a denial of service.
This issue only affected Ubuntu 24.04 LTS and Ubuntu 24.10.
(CVE-2025-26466)
Fixed packages 3
| Release | Package | Fixed in |
|---|---|---|
| Ubuntu · 20.04 LTS 20.04:LTS | openssh | 1:8.2p1-4ubuntu0.12 |
| Ubuntu · 22.04 LTS 22.04:LTS | openssh | 1:8.9p1-3ubuntu0.11 |
| Ubuntu · 24.04 LTS 24.04:LTS | openssh | 1:9.6p1-3ubuntu13.8 |
Vulnerabilities 2
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Medium 6.8CVE-2025-26465 Public exploit
Openssh: machine-in-the-middle attack if verifyhostkeydns is enabled
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 cond…
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Medium 5.9
Openssh: denial-of-service in openssh
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 k…