Severity: critical
CVSS 3.1: 9.1 (critical) CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Affected versions:
- Apache MINA SSHD (org.apache.sshd:sshd-core) 2.0.0 before 2.20.0
- Apache MINA SSHD (org.apache.sshd:sshd-core) 3.0.0-M1 before 3.0.0-M6
Description:
Authentication bypass in sshd-core in Apache MINA SSHD versions 2.0.0 to 2.19.0
and 3.0.0-M1 to 3.0.0-M5 for a certain (presumed rare) way to implement an SSH
server.
Apache MINA SSHD is a Java library for client- and server-side SSH. In the
server part of the library, a mechanism to perform "asynchronous
authentication" exists. A server implemented with Apache MINA SSHD must contain
explicit code to make use of this feature. The implementation of this feature
was flawed and could potentially lead to skipping checking the signature in
public-key or hostbased authentication, or returning a wrong result.
Users are recommended to upgrade to Apache MINA SSHD 2.20.0 or 3.0.0-M6, which
fix the logic error and which additionally forbid the use of this "asynchronous
authentication" mechanism with the public-key or hostbased authentication
schemes: if used, the SSH session will be closed and the server will log an
entry indicating that asynchronous authentication may be used only with
password or keyboard-interactive authentication.
Credit:
Chris Jarret-Davies, OpenAI Security Research Team (finder)
References:
https://mina.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-77185
