Denial of Service (DoS) Affecting libssh package, versions [0,]


Severity

Recommended
0.0
medium
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.3% (22nd percentile)

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  • Snyk IDSNYK-CONAN-LIBSSH-18305721
  • published25 Jul 2026
  • disclosed21 Jul 2026
  • creditUnknown

Introduced: 21 Jul 2026

NewCVE-2026-59848  (opens in a new tab)
CWE-400  (opens in a new tab)

How to fix?

A fix was pushed into the master branch but not yet published.

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS) in the handling of SFTP responses with unknown request IDs. An attacker can cause unbounded memory growth and disrupt client operations by sending specially crafted responses from a malicious SFTP server.

Workaround

This vulnerability can be mitigated by avoiding connections to untrusted SFTP servers.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

  • High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

  • Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

CVSS Base Scores

version 4.0
version 3.1