CVE-2026-56624

Received Received - Intake

Improper Certificate Validation in Apache MINA SSHD

Publication date: 2026-07-20

Last updated on: 2026-07-20

Assigner: Apache Software Foundation

Description

Improper certificate validation in Apache MINA SSHD (server-side). Apache MINA SSHD is a Java library for client-side and server-side SSH. Server-side OpenSSH user certificate validation during user authentication in an Apache MINA SSHD server did not check for the unsupported force-command or verify-required options that could be embedded in the certificate, nor did it validate these options. As a result it was possible that a user could authenticate with such a certificate that included a force-command option but still was able to execute other commands. What other command exactly would be available to the user depends on the implementation of the server. This issue is fixed in Apache MINA SSHD 2.19.0 and 3.0.0-M5. Applications are advised to upgrade to these versions. The fix rejects OpenSSH user certificates that include these options, since Apache MINA SSHD implements neither force-command nor sk-*[email protected] user certificates (which are the only ones for which verify-required would make sense).

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-07-20

Last Modified

2026-07-20

Generated

2026-07-21

AI Q&A

2026-07-21

EPSS Evaluated

N/A

NVD

CVE-2026-56624

Affected Vendors & Products

Vendor	Product	Version / Range
apache	mina	sshd

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-295	The product does not validate, or incorrectly validates, a certificate.

Attack-Flow Graph

Executive Summary

This vulnerability involves improper certificate validation in Apache MINA SSHD server-side. During user authentication, the server fails to check for unsupported options like force-command or verify-required embedded in OpenSSH user certificates. This allows users to authenticate with certificates containing force-command but still execute other commands, depending on server implementation.

Detection Guidance

Detection involves checking the Apache MINA SSHD server version. If the version is below 2.19.0 or 3.0.0-M5, the system is vulnerable. Use commands like 'java -jar mina-sshd-server.jar --version' or inspect dependency files (e.g., pom.xml) for the version number.

Impact Analysis

An attacker could exploit this to bypass intended restrictions on command execution, potentially running unauthorized commands on the server. This could lead to unauthorized access, data manipulation, or further compromise of the system if the server allows additional commands beyond what the certificate permits.

Compliance Impact

This vulnerability could lead to unauthorized command execution, potentially violating access controls required by GDPR (data protection) and HIPAA (health data security). Non-compliance may result from unauthorized data access or modification, undermining confidentiality and integrity requirements of these regulations.

Mitigation Strategies

Upgrade Apache MINA SSHD to version 2.19.0 or 3.0.0-M5 or later. This can be done by updating dependencies in your project or replacing the library files. Ensure no OpenSSH user certificates with force-command or verify-required options are accepted.

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