diff --git a/go.mod b/go.mod
index 2a022ddf8..f0e450ff1 100644
--- a/go.mod
+++ b/go.mod
@@ -27,7 +27,7 @@ require (
 	github.com/pkg/xattr v0.4.10
 	github.com/prometheus/client_golang v1.20.5
 	github.com/stretchr/testify v1.10.0
-	golang.org/x/crypto v0.33.0
+	golang.org/x/crypto v0.35.0
 	golang.org/x/net v0.35.0
 	golang.org/x/sys v0.30.0
 	google.golang.org/grpc v1.70.0
diff --git a/go.sum b/go.sum
index 390ee48f4..80d377868 100644
--- a/go.sum
+++ b/go.sum
@@ -2523,8 +2523,8 @@ golang.org/x/crypto v0.24.0/go.mod h1:Z1PMYSOR5nyMcyAVAIQSKCDwalqy85Aqn1x3Ws4L5D
 golang.org/x/crypto v0.25.0/go.mod h1:T+wALwcMOSE0kXgUAnPAHqTLW+XHgcELELW8VaDgm/M=
 golang.org/x/crypto v0.26.0/go.mod h1:GY7jblb9wI+FOo5y8/S2oY4zWP07AkOJ4+jxCqdqn54=
 golang.org/x/crypto v0.28.0/go.mod h1:rmgy+3RHxRZMyY0jjAJShp2zgEdOqj2AO7U0pYmeQ7U=
-golang.org/x/crypto v0.33.0 h1:IOBPskki6Lysi0lo9qQvbxiQ+FvsCC/YWOecCHAixus=
-golang.org/x/crypto v0.33.0/go.mod h1:bVdXmD7IV/4GdElGPozy6U7lWdRXA4qyRVGJV57uQ5M=
+golang.org/x/crypto v0.35.0 h1:b15kiHdrGCHrP6LvwaQ3c03kgNhhiMgvlhxHQhmg2Xs=
+golang.org/x/crypto v0.35.0/go.mod h1:dy7dXNW32cAb/6/PRuTNsix8T+vJAqvuIy5Bli/x0YQ=
 golang.org/x/exp v0.0.0-20180321215751-8460e604b9de/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20180807140117-3d87b88a115f/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
diff --git a/vendor/golang.org/x/crypto/ssh/handshake.go b/vendor/golang.org/x/crypto/ssh/handshake.go
index fef687db0..c9202b05d 100644
--- a/vendor/golang.org/x/crypto/ssh/handshake.go
+++ b/vendor/golang.org/x/crypto/ssh/handshake.go
@@ -25,6 +25,11 @@ const debugHandshake = false
 // quickly.
 const chanSize = 16
 
+// maxPendingPackets sets the maximum number of packets to queue while waiting
+// for KEX to complete. This limits the total pending data to maxPendingPackets
+// * maxPacket bytes, which is ~16.8MB.
+const maxPendingPackets = 64
+
 // keyingTransport is a packet based transport that supports key
 // changes. It need not be thread-safe. It should pass through
 // msgNewKeys in both directions.
@@ -73,11 +78,19 @@ type handshakeTransport struct {
 	incoming  chan []byte
 	readError error
 
-	mu               sync.Mutex
-	writeError       error
-	sentInitPacket   []byte
-	sentInitMsg      *kexInitMsg
-	pendingPackets   [][]byte // Used when a key exchange is in progress.
+	mu sync.Mutex
+	// Condition for the above mutex. It is used to notify a completed key
+	// exchange or a write failure. Writes can wait for this condition while a
+	// key exchange is in progress.
+	writeCond      *sync.Cond
+	writeError     error
+	sentInitPacket []byte
+	sentInitMsg    *kexInitMsg
+	// Used to queue writes when a key exchange is in progress. The length is
+	// limited by pendingPacketsSize. Once full, writes will block until the key
+	// exchange is completed or an error occurs. If not empty, it is emptied
+	// all at once when the key exchange is completed in kexLoop.
+	pendingPackets   [][]byte
 	writePacketsLeft uint32
 	writeBytesLeft   int64
 	userAuthComplete bool // whether the user authentication phase is complete
@@ -134,6 +147,7 @@ func newHandshakeTransport(conn keyingTransport, config *Config, clientVersion,
 
 		config: config,
 	}
+	t.writeCond = sync.NewCond(&t.mu)
 	t.resetReadThresholds()
 	t.resetWriteThresholds()
 
@@ -260,6 +274,7 @@ func (t *handshakeTransport) recordWriteError(err error) {
 	defer t.mu.Unlock()
 	if t.writeError == nil && err != nil {
 		t.writeError = err
+		t.writeCond.Broadcast()
 	}
 }
 
@@ -363,6 +378,8 @@ write:
 			}
 		}
 		t.pendingPackets = t.pendingPackets[:0]
+		// Unblock writePacket if waiting for KEX.
+		t.writeCond.Broadcast()
 		t.mu.Unlock()
 	}
 
@@ -577,11 +594,20 @@ func (t *handshakeTransport) writePacket(p []byte) error {
 	}
 
 	if t.sentInitMsg != nil {
-		// Copy the packet so the writer can reuse the buffer.
-		cp := make([]byte, len(p))
-		copy(cp, p)
-		t.pendingPackets = append(t.pendingPackets, cp)
-		return nil
+		if len(t.pendingPackets) < maxPendingPackets {
+			// Copy the packet so the writer can reuse the buffer.
+			cp := make([]byte, len(p))
+			copy(cp, p)
+			t.pendingPackets = append(t.pendingPackets, cp)
+			return nil
+		}
+		for t.sentInitMsg != nil {
+			// Block and wait for KEX to complete or an error.
+			t.writeCond.Wait()
+			if t.writeError != nil {
+				return t.writeError
+			}
+		}
 	}
 
 	if t.writeBytesLeft > 0 {
@@ -598,6 +624,7 @@ func (t *handshakeTransport) writePacket(p []byte) error {
 
 	if err := t.pushPacket(p); err != nil {
 		t.writeError = err
+		t.writeCond.Broadcast()
 	}
 
 	return nil
diff --git a/vendor/modules.txt b/vendor/modules.txt
index ede1b41bb..812bd5086 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -835,8 +835,8 @@ go.uber.org/zap/internal/pool
 go.uber.org/zap/internal/stacktrace
 go.uber.org/zap/zapcore
 go.uber.org/zap/zapgrpc
-# golang.org/x/crypto v0.33.0
-## explicit; go 1.20
+# golang.org/x/crypto v0.35.0
+## explicit; go 1.23.0
 golang.org/x/crypto/argon2
 golang.org/x/crypto/blake2b
 golang.org/x/crypto/blowfish