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6.5Medium

Libssh Libssh

CVE-2025-5449

A flaw was found in the SFTP server message decoding logic of libssh. The issue occurs due to an incorrect packet length check that allows an integer overflow when handling large payload sizes on 32-bit systems. This issue leads to failed memory allocation and causes the server process to crash, resulting in a denial of service.

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

  1. 1Check whether your company or your suppliers run Libssh, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

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Scoring

CVSS
6.5 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-190
Assigned by
secalert@redhat.com

Dates

Published
2025-07-25
Last modified
2026-08-31
Sources
NVD

Affected products

  • Libssh Libssh0.11.0, 0.11.1

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

References