Security Advisory

CVE-2026-56854

7.5
HIGH

Vulnerability Description

The source-address critical option in the Permissions returned by an authentication callback was only enforced for the PublicKeyCallback and VerifiedPublicKeyCallback paths, extending the fix for CVE-2026-46595. Permissions returned by the PasswordCallback, KeyboardInteractiveCallback, NoClientAuthCallback, and GSSAPIWithMICConfig.AllowLogin callbacks were not validated against the client's remote address, so a source-address restriction set by those callbacks was silently ignored. The check is now applied to the Permissions returned by any authentication callback.
Published Date August 28, 2026
Official Source NIST NVD Advisory