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-2026-39831 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-2026-46598 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-2026-42508 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-2026-46595

The golang.org/x/crypto/ssh library is affected by an authorization bypass vulnerability. If an SSH server configuration uses a callback other than a public key , the system fails to perform source-address validation . This issue was previously addressed in CVE-2024-45337 but persists in specific...

CVE-2026-46595

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-2026-39830 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-2026-39834

An integer overflow in the internal payload size calculation of the Go programming language (specifically golang.org/x/crypto/ssh) allows a remote attacker to cause a denial of service . When writing data larger than 4GB in a single Write call on an SSH channel, the write loop spins indefinitely,...

CVE-2026-39830

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-2026-39831

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-2026-42508 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

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-2026-39830 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-2026-39834 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-2026-39827 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

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-2026-39834 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-2026-46595 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-2026-39832 Invoking agent constraints dropped when forwarding keys in golang.org/x/crypto/ssh/agent

When adding a key to a remote agent constraint extensions such as [email protected] were not serialized in the request. Destination restrictions were silently stripped when forwarding keys, allowing unrestricted use of the key on the remote host. The client now serializes all...