CVE-2025-5372

A flaw was found in libssh versions built with OpenSSL versions older than 3.0, specifically in the ssh_kdf() function responsible for key derivation. Due to inconsistent interpretation of return values where OpenSSL uses 0 to indicate failure and libssh uses 0 for success—the function may mistakenly return a success status even when key derivation fails. This results in uninitialized cryptographic key buffers being used in subsequent communication, potentially compromising SSH sessions' confidentiality, integrity, and availability.

What this means for your business

It affects Libssh. It matters if your company, or a supplier that handles your data, runs it.
An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.

What to do

1Check whether your company or your suppliers run Libssh, and which version. The affected versions are listed further down this page.
2If you do, follow the vendor's guidance. No patch reference has been published yet.

Not sure if your company is exposed?

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Scoring

CVSS: 5.0 (v3.1)
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
Weakness: CWE-682
Assigned by: secalert@redhat.com

Dates

Published: 2025-07-04
Last modified: 2026-09-01
Sources: NVD

Affected products

Libssh Libssh- 0.11.2
Redhat Openshift Container Platform4.0
Redhat Enterprise Linux6.0, 7.0, 8.0, 9.0, 10.0

As listed in the NVD configuration data. Not a statement about your estate.