diff --git a/src/core/ext/filters/client_channel/subchannel.c b/src/core/ext/filters/client_channel/subchannel.c
index 967e571221c..b2de85c4a12 100644
--- a/src/core/ext/filters/client_channel/subchannel.c
+++ b/src/core/ext/filters/client_channel/subchannel.c
@@ -615,7 +615,7 @@ void grpc_connected_subchannel_ping(grpc_exec_ctx *exec_ctx,
   elem->filter->start_transport_op(exec_ctx, elem, op);
 }
 
-static void publish_transport_locked(grpc_exec_ctx *exec_ctx,
+static bool publish_transport_locked(grpc_exec_ctx *exec_ctx,
                                      grpc_subchannel *c) {
   grpc_connected_subchannel *con;
   grpc_channel_stack *stk;
@@ -631,15 +631,16 @@ static void publish_transport_locked(grpc_exec_ctx *exec_ctx,
   if (!grpc_channel_init_create_stack(exec_ctx, builder,
                                       GRPC_CLIENT_SUBCHANNEL)) {
     grpc_channel_stack_builder_destroy(exec_ctx, builder);
-    abort(); /* TODO(ctiller): what to do here (previously we just crashed) */
+    return false;
   }
   grpc_error *error = grpc_channel_stack_builder_finish(
       exec_ctx, builder, 0, 1, connection_destroy, NULL, (void **)&con);
   if (error != GRPC_ERROR_NONE) {
+    grpc_transport_destroy(exec_ctx, c->connecting_result.transport);
     gpr_log(GPR_ERROR, "error initializing subchannel stack: %s",
             grpc_error_string(error));
     GRPC_ERROR_UNREF(error);
-    abort(); /* TODO(ctiller): what to do here? */
+    return false;
   }
   stk = CHANNEL_STACK_FROM_CONNECTION(con);
   memset(&c->connecting_result, 0, sizeof(c->connecting_result));
@@ -656,7 +657,7 @@ static void publish_transport_locked(grpc_exec_ctx *exec_ctx,
     grpc_channel_stack_destroy(exec_ctx, stk);
     gpr_free(con);
     GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting");
-    return;
+    return false;
   }
 
   /* publish */
@@ -678,6 +679,7 @@ static void publish_transport_locked(grpc_exec_ctx *exec_ctx,
   /* signal completion */
   grpc_connectivity_state_set(exec_ctx, &c->state_tracker, GRPC_CHANNEL_READY,
                               GRPC_ERROR_NONE, "connected");
+  return true;
 }
 
 static void subchannel_connected(grpc_exec_ctx *exec_ctx, void *arg,
@@ -688,8 +690,9 @@ static void subchannel_connected(grpc_exec_ctx *exec_ctx, void *arg,
   GRPC_SUBCHANNEL_WEAK_REF(c, "connected");
   gpr_mu_lock(&c->mu);
   c->connecting = false;
-  if (c->connecting_result.transport != NULL) {
-    publish_transport_locked(exec_ctx, c);
+  if (c->connecting_result.transport != NULL &&
+      publish_transport_locked(exec_ctx, c)) {
+    /* do nothing, transport was published */
   } else if (c->disconnected) {
     GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, c, "connecting");
   } else {
diff --git a/src/core/lib/channel/connected_channel.c b/src/core/lib/channel/connected_channel.c
index 22caf243737..d8985268eba 100644
--- a/src/core/lib/channel/connected_channel.c
+++ b/src/core/lib/channel/connected_channel.c
@@ -128,7 +128,9 @@ static grpc_error *init_channel_elem(grpc_exec_ctx *exec_ctx,
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
                                  grpc_channel_element *elem) {
   channel_data *cd = (channel_data *)elem->channel_data;
-  grpc_transport_destroy(exec_ctx, cd->transport);
+  if (cd->transport) {
+    grpc_transport_destroy(exec_ctx, cd->transport);
+  }
 }
 
 static char *con_get_peer(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {
diff --git a/src/core/lib/security/transport/client_auth_filter.c b/src/core/lib/security/transport/client_auth_filter.c
index f526653ffa3..1f0daf73253 100644
--- a/src/core/lib/security/transport/client_auth_filter.c
+++ b/src/core/lib/security/transport/client_auth_filter.c
@@ -343,8 +343,16 @@ static grpc_error *init_channel_elem(grpc_exec_ctx *exec_ctx,
                                      grpc_channel_element_args *args) {
   grpc_security_connector *sc =
       grpc_security_connector_find_in_args(args->channel_args);
+  if (sc == NULL) {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "Security connector missing from client auth filter args");
+  }
   grpc_auth_context *auth_context =
       grpc_find_auth_context_in_args(args->channel_args);
+  if (auth_context == NULL) {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "Auth context missing from client auth filter args");
+  }
 
   /* grab pointers to our data from the channel element */
   channel_data *chand = elem->channel_data;
@@ -353,8 +361,6 @@ static grpc_error *init_channel_elem(grpc_exec_ctx *exec_ctx,
      handle the case that there's no 'next' filter to call on the up or down
      path */
   GPR_ASSERT(!args->is_last);
-  GPR_ASSERT(sc != NULL);
-  GPR_ASSERT(auth_context != NULL);
 
   /* initialize members */
   chand->security_connector =
diff --git a/test/core/end2end/fuzzers/api_fuzzer_corpus/clusterfuzz-testcase-minimized-5175380371570688 b/test/core/end2end/fuzzers/api_fuzzer_corpus/clusterfuzz-testcase-minimized-5175380371570688
new file mode 100644
index 00000000000..9c7aebc63a2
Binary files /dev/null and b/test/core/end2end/fuzzers/api_fuzzer_corpus/clusterfuzz-testcase-minimized-5175380371570688 differ
diff --git a/tools/run_tests/generated/tests.json b/tools/run_tests/generated/tests.json
index 058127862ea..2928b870c91 100644
--- a/tools/run_tests/generated/tests.json
+++ b/tools/run_tests/generated/tests.json
@@ -85302,6 +85302,29 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/api_fuzzer_corpus/clusterfuzz-testcase-minimized-5175380371570688"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "api_fuzzer_one_entry", 
+    "platforms": [
+      "mac", 
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/api_fuzzer_corpus/crash-0597bbdd657fa4ed14443994c9147a1a7bbc205f"