UBUNTU-CVE-2026-39828

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...

CVE-2026-39834 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-2026-42508 Invoking auth bypass via unenforced @revoked status in golang.org/x/crypto/ssh/knownhosts

Previously, a revoked 'SignatureKey' belonging to a CA was not correctly checked for revocation. Now, both the 'key' and 'key.SignatureKey' are checked for @revoked...

CVE-2026-39830 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-2026-39827 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...

CVE-2026-46598 Invoking pathological inputs can lead to client panic in golang.org/x/crypto/ssh/agent

For certain crafted inputs, a 'ed25519.PrivateKey' was created by casting malformed wire bytes, leading to a panic when used...

CVE-2026-39834 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-2026-42508 Invoking auth bypass via unenforced @revoked status in golang.org/x/crypto/ssh/knownhosts

Previously, a revoked 'SignatureKey' belonging to a CA was not correctly checked for revocation. Now, both the 'key' and 'key.SignatureKey' are checked for @revoked...

CVE-2026-39827 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...

CVE-2026-39834

CVE-2026-39834 concerns a flaw in golang.org/x/crypto/ssh where writing data larger than 4GB in a single Write on an SSH channel triggers an integer overflow in the internal payload size calculation. The overflow causes the write loop to spin indefinitely, sending empty packets and making no prog...

CVE-2026-46595 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-2026-46595

CVE-2026-46595 affects golang.org/x/crypto/ssh. The issue arises when VerifiedPublicKeyCallback is invoked with a callback type other than public key, causing the source-address validation to be bypassed and enabling an authorization bypass. The description notes this is a continuation of CVE-202...

CVE-2026-39831 Invoking bypass of FIDO/U2F security keys physical interaction in golang.org/x/crypto/ssh

The Verify method for FIDO/U2F security key types [email protected], [email protected] 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,...

CVE-2026-39830 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-2026-39828

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...

CVE-2026-39828 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...

CVE-2026-46597 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-2026-46597 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-2026-39833

The CVE-2026-39833 issue affects the in-memory keyring used by golang.org/x/crypto/ssh/agent. The ConfirmBeforeUse constraint was silently accepted but not enforced by NewKeyring(), allowing keys to sign without a required confirmation prompt and without notifying the caller. The patch fixes this...

CVE-2026-46597 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...