CVE-2026-56624: Apache MINA SSHD: SSH certificate options lack validations
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--cert-v01 user certificates (which are the only ones for which verify-required would make sense).
Other sources
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--cert-v01@openssh.com user certificates (which are the only ones for which verify-required would make sense).
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Apache MINA SSHDto a version that resolves this vulnerability.Fixed in 2.19.0Patch CVE-2026-56624 - Upgrade
Upgrade
Apache MINA SSHDto a version that resolves this vulnerability.Fixed in 3.0.0-M5Patch CVE-2026-56624
Event History
Frequently Asked Questions
What is the severity of CVE-2026-56624?
The CVE-2026-56624 vulnerability has a high severity rating of 7.3.
How does CVE-2026-56624 affect Apache MINA SSHD?
CVE-2026-56624 affects Apache MINA SSHD by allowing improper validation of SSH certificates during user authentication.
What are the potential consequences of CVE-2026-56624?
The potential consequences include unauthorized access due to unsupported SSH certificate options not being validated.
How do I fix CVE-2026-56624?
To fix CVE-2026-56624, ensure you update to the latest version of Apache MINA SSHD that includes the necessary validation checks.
Is user data at risk with CVE-2026-56624?
Yes, user data is at risk as the vulnerability can lead to improper authentication and unauthorized access.