CVE-2026-56854

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 Aug 28, 2026
  • CVSS 7.5 high
  • 0.4% chance of exploitation in the next 30 days (EPSS)

Affected software

In the news

CVE-2026-56854 at the National Vulnerability Database