Memory Leak Affecting libssh package, versions <0.8.0~20170825.94fa1e38-1ubuntu0.7+esm6


Severity

Recommended
0.0
low
0
10

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.4% (33rd percentile)

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  • Snyk IDSNYK-UBUNTU1804-LIBSSH-12613460
  • published26 Feb 2026
  • disclosed9 Sept 2025

Introduced: 9 Sep 2025

CVE-2025-8277  (opens in a new tab)
CWE-401  (opens in a new tab)

How to fix?

Upgrade Ubuntu:18.04 libssh to version 0.8.0~20170825.94fa1e38-1ubuntu0.7+esm6 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:18.04 relevant fixed versions and status.

A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side, particularly when using libgcrypt, which impacts application stability and availability.

CVSS Base Scores

version 3.1