Incorrect Authorization Affecting golang.org/x/crypto/ssh package, versions <0.55.0
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published30 Aug 2026
- disclosed28 Aug 2026
- creditLongwei Wang
Introduced: 28 Aug 2026
NewCVE-2026-56854 Â (opens in a new tab)How to fix?
Upgrade golang.org/x/crypto/ssh to version 0.55.0 or higher.
Overview
golang.org/x/crypto/ssh is a SSH client and server
Affected versions of this package are vulnerable to Incorrect Authorization in NewServerConn, which applied the critical option from the Permissions returned by an authentication callback only on the PublicKeyCallback and VerifiedPublicKeyCallback paths and silently ignored it for PasswordCallback, KeyboardInteractiveCallback, NoClientAuthCallback, and GSSAPIWithMICConfig.AllowLogin. An attacker can connect from an address the restriction was meant to exclude by authenticating through one of those unenforced callback paths. This affects only servers that set a source-address restriction from a password, keyboard-interactive, no-client-auth, or GSSAPI authentication callback and rely on it being enforced.
Note: This is a bypass of the fix for the vulnerability described in CVE-2026-46595.