CVE-2026-83540: wolfSSHd on Windows race condition leading to logon token reused across connections
When password or public key authentication is used with the Windows port of wolfSSHd, the Windows logon token acquired for one authenticated connection is not released before a token is acquired for a subsequent connection, resulting in user login poisoning between connections. A less privileged user with a valid account on the server can exploit this to force a login as a more privileged user. The vulnerability was introduced with the initial Windows port of wolfSSHd in wolfSSH version 1.4.15 and affects all versions through 1.5.0. Non-Windows builds of wolfSSHd are not affected.
Affected Software
Event History
Frequently Asked Questions
Which deployments are affected?
Only the Windows port of wolfSSHd is affected. The issue was introduced in wolfSSH 1.4.15 and affects versions through 1.5.0; non-Windows wolfSSHd builds are not affected.
What does an attacker need to exploit this issue?
An attacker needs a valid, less-privileged account on the affected server and must authenticate using password or public key authentication. They can then exploit token reuse between connections to force a login as a more privileged user.
Are password and public-key authentication both affected?
Yes. The issue occurs when wolfSSHd on Windows uses either password authentication or public-key authentication, because the Windows logon token from one authenticated connection is not released before another token is acquired.