Vulnerabilidades do Golang.org/x/crypto Golang.org/x/crypto/ssh

CVE-2026-78662 Alta · 7.5 CWE-770 02/09/2026

Prevent DoS on deadlocked undecided channel in golang.org/x/crypto/ssh

Previously, a channel registered in the mux's chanList is not usable until it is established. A malicious peer was able flood the channel's incomingRequests, deadlocking the entire connection. Now, we add an atomic established state, set when a channel becomes usable. Until such a time, handlePacket drops every packet other than the open confirmation/failure, without blocking and without tearing down the connection.

CVE-2026-56855 Alta · 7.5 CWE-770 02/09/2026

Prevent DoS on deadlocked established channel in golang.org/x/crypto/ssh

Previously, after a channel has been established, a malicious peer could send crafted messages that would deadlock the entire connection. Now, we handle all RFC 4254 channel messages; global requests are handled explicitly. Then, treat all other messages as a protocol error and tear the connection down instead of buffering and blocking.

CVE-2026-56854 Alta · 7.5 CWE-863 28/08/2026

Source-address critical option not enforced for non-public-key auth callbacks in golang.org/x/crypto/ssh

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.

CVE-2026-46597 Alta · 7.5 CWE-704 22/05/2026

Invoking byte arithmetic causes underflow and panic in golang.org/x/crypto/ssh

An incorrectly placed cast from bytes to int allowed for server-side panic in the AES-GCM packet decoder for well-crafted inputs.

CVE-2026-46595 Crítica · 10.0 CWE-863 22/05/2026

Invoking VerifiedPublicKeyCallback permissions skip enforcement in golang.org/x/crypto/ssh

Previously, CVE-2024-45337 fixed an authorization bypass for misused ssh server configurations; if any other type of callback is passed other than public key, then the source-address validation would be skipped.

CVE-2026-39835 Média · 5.3 CWE-295 22/05/2026

Invoking server panic during CheckHostKey/Authenticate in golang.org/x/crypto/ssh

SSH servers which use CertChecker as a public key callback without setting IsUserAuthority or IsHostAuthority could be caused to panic by a client presenting a certificate. CertChecker now returns an error instead of panicking when these callbacks are nil.

CVE-2026-39834 Crítica · 9.1 CWE-190 22/05/2026

Invoking infinite loop on large channel writes in golang.org/x/crypto/ssh

When writing data larger than 4GB in a single Write call on an SSH channel, an integer overflow in the internal payload size calculation caused the write loop to spin indefinitely, sending empty packets without making progress. The size comparison now uses int64 to prevent truncation.

CVE-2026-39831 Crítica · 9.1 CWE-862 22/05/2026

Invoking bypass of FIDO/U2F security keys physical interaction in golang.org/x/crypto/ssh

The Verify() method for FIDO/U2F security key types (sk-ecdsa-sha2-nistp256@openssh.com, sk-ssh-ed25519@openssh.com) did not check the User Presence flag. Signatures generated without physical touch were accepted, allowing unattended use of a hardware security key. To restore the previous behavior, return a "no-touch-required" extension in Permissions.Extensions from PublicKeyCallback.

CVE-2026-39830 Crítica · 9.1 CWE-119 22/05/2026

Invoking client can cause server deadlock on unexpected responses in golang.org/x/crypto/ssh

A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded.

CVE-2026-39829 Alta · 7.5 CWE-347 22/05/2026

Invoking pathological RSA/DSA parameters may cause DoS in golang.org/x/crypto/ssh

The RSA and DSA public key parsers did not enforce size limits on key parameters. A crafted public key with an excessively large modulus or DSA parameter could cause several minutes of CPU consumption during signature verification. This could be triggered by unauthenticated clients during public key authentication. RSA moduli are now limited to 8192 bits, and DSA parameters are validated per FIPS 186-2.

CVE-2026-39828 Média · 6.3 CWE-295 22/05/2026

Invoking bypass of certificate restrictions in golang.org/x/crypto/ssh

When an SSH server authentication callback returned PartialSuccessError with non-nil Permissions, those permissions were silently discarded, potentially dropping certificate restrictions such as force-command after a second factor succeeded. Returning non-nil Permissions with PartialSuccessError now results in a connection error.

CVE-2026-39827 Média · 6.5 CWE-924 22/05/2026

Invoking memory leak when rejecting channels can lead to DoS in golang.org/x/crypto/ssh

An authenticated SSH client that repeatedly opened channels which were rejected by the server caused unbounded memory growth, eventually crashing the server process and affecting all connected users. Rejected channels are now properly removed from the connection's internal state and released for garbage collection.

CVE-2025-58181 Média · 5.3 CWE-770 19/11/2025

Unbounded memory consumption in golang.org/x/crypto/ssh

SSH servers parsing GSSAPI authentication requests do not validate the number of mechanisms specified in the request, allowing an attacker to cause unbounded memory consumption.