Use After Free Affecting libssh package, versions <0.9.3-2ubuntu2.5+esm1


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.01% (3rd percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications

Snyk Learn

Learn about Use After Free vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-UBUNTU2004-LIBSSH-10500672
  • published21 Aug 2025
  • disclosed22 Jul 2025

Introduced: 22 Jul 2025

CVE-2025-4878  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Ubuntu:20.04 libssh to version 0.9.3-2ubuntu2.5+esm1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libssh package and not the libssh package as distributed by Ubuntu. See How to fix? for Ubuntu:20.04 relevant fixed versions and status.

A vulnerability was found in libssh, where an uninitialized variable exists under certain conditions in the privatekey_from_file() function. This flaw can be triggered if the file specified by the filename doesn't exist and may lead to possible signing failures or heap corruption.

CVSS Base Scores

version 3.1