Apache MINA SSHD up to 2.18.0/3.0.0-M4 certificate validation

Summaryinfo

A vulnerability was found in Apache MINA SSHD up to 2.18.0/3.0.0-M4. It has been classified as problematic. This impacts an unknown function. Performing a manipulation results in certificate validation. This vulnerability was named CVE-2026-56624. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability classified as problematic has been found in Apache MINA SSHD up to 2.18.0/3.0.0-M4. This affects an unknown code block. The manipulation with an unknown input leads to a certificate validation vulnerability. CWE is classifying the issue as CWE-295. The product does not validate, or incorrectly validates, a certificate. This is going to have an impact on integrity. The summary by CVE is:

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).

It is possible to read the advisory at lists.apache.org. This vulnerability is uniquely identified as CVE-2026-56624 since 06/22/2026. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/20/2026). The attack technique deployed by this issue is T1587.003 according to MITRE ATT&CK.

Upgrading to version 2.19.0 or 3.0.0-M5 eliminates this vulnerability.

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Productinfo

Type

• SSH Server Software

Vendor

• Apache

Name

• MINA SSHD

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9
• 2.10
• 2.11
• 2.12
• 2.13
• 2.14
• 2.15
• 2.16
• 2.17
• 2.18.0
• 3.0.0-M4

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

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CPE 2.2info

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