CVE-2026-83540: wolfSSL Wolfssh

High severity, CVSS 7.7. EPSS: 0.3% chance of exploitation in the next 30 days.

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 products

• wolfSSL Wolfssh: from 1.4.15, up to and including 1.5.0

Published 2026-10-07. Last modified 2026-10-07.