diff --git a/src/basic/env-util.h b/src/basic/env-util.h
index 28338a1458..4063517660 100644
--- a/src/basic/env-util.h
+++ b/src/basic/env-util.h
@@ -3,6 +3,8 @@
 
 #include "basic-forward.h"
 
+#define ENVIRONMENT_ASSIGNMENTS_MAX 16384U
+
 size_t sc_arg_max(void);
 
 bool env_name_is_valid(const char *e);
diff --git a/src/core/dbus-manager.c b/src/core/dbus-manager.c
index 88de34c4ea..5b41e1befe 100644
--- a/src/core/dbus-manager.c
+++ b/src/core/dbus-manager.c
@@ -1251,6 +1251,14 @@ static int list_units_filtered(sd_bus_message *message, void *userdata, sd_bus_e
 
         /* Anyone can call this method */
 
+        if (strv_length(states) > MANAGER_MAX_STATES_PER_CALL)
+                return sd_bus_error_set(reterr_error, SD_BUS_ERROR_LIMITS_EXCEEDED,
+                                        "Too many states in a single query.");
+
+        if (strv_length(patterns) > MANAGER_MAX_PATTERNS_PER_CALL)
+                return sd_bus_error_set(reterr_error, SD_BUS_ERROR_LIMITS_EXCEEDED,
+                                        "Too many patterns in a single query.");
+
         r = sd_bus_message_new_method_return(message, &reply);
         if (r < 0)
                 return r;
@@ -1434,6 +1442,10 @@ static int dump_impl(
 
         assert(message);
 
+        if (strv_length(patterns) > MANAGER_MAX_PATTERNS_PER_CALL)
+                return sd_bus_error_set(reterr_error, SD_BUS_ERROR_LIMITS_EXCEEDED,
+                                        "Too many patterns in a single query.");
+
         /* 'status' access is the bare minimum always needed for this, as the policy might straight out
          * forbid a client from querying any information from systemd, regardless of any rate limiting. */
         r = mac_selinux_access_check(message, "status", reterr_error);
@@ -1880,6 +1892,10 @@ static int method_set_environment(sd_bus_message *message, void *userdata, sd_bu
         r = sd_bus_message_read_strv(message, &plus);
         if (r < 0)
                 return r;
+
+        if (strv_length(plus) > ENVIRONMENT_ASSIGNMENTS_MAX)
+                return sd_bus_error_set(reterr_error, SD_BUS_ERROR_LIMITS_EXCEEDED,
+                                        "Too many environment assignments in a single query.");
         if (!strv_env_is_valid(plus))
                 return sd_bus_error_set(reterr_error, SD_BUS_ERROR_INVALID_ARGS, "Invalid environment assignments");
 
@@ -1911,6 +1927,9 @@ static int method_unset_environment(sd_bus_message *message, void *userdata, sd_
         if (r < 0)
                 return r;
 
+        if (strv_length(minus) > ENVIRONMENT_ASSIGNMENTS_MAX)
+                return sd_bus_error_set(reterr_error, SD_BUS_ERROR_LIMITS_EXCEEDED,
+                                        "Too many environment variable names in a single query.");
         if (!strv_env_name_or_assignment_is_valid(minus))
                 return sd_bus_error_set(reterr_error, SD_BUS_ERROR_INVALID_ARGS,
                                         "Invalid environment variable names or assignments");
@@ -1947,6 +1966,9 @@ static int method_unset_and_set_environment(sd_bus_message *message, void *userd
         if (r < 0)
                 return r;
 
+        if (strv_length(plus) > ENVIRONMENT_ASSIGNMENTS_MAX || strv_length(minus) > ENVIRONMENT_ASSIGNMENTS_MAX)
+                return sd_bus_error_set(reterr_error, SD_BUS_ERROR_LIMITS_EXCEEDED,
+                                        "Too many environment variable names or assignments in a single query.");
         if (!strv_env_name_or_assignment_is_valid(minus))
                 return sd_bus_error_set(reterr_error, SD_BUS_ERROR_INVALID_ARGS,
                                         "Invalid environment variable names or assignments");
@@ -2177,6 +2199,14 @@ static int list_unit_files_by_patterns(sd_bus_message *message, void *userdata,
 
         /* Anyone can call this method */
 
+        if (strv_length(states) > MANAGER_MAX_STATES_PER_CALL)
+                return sd_bus_error_set(reterr_error, SD_BUS_ERROR_LIMITS_EXCEEDED,
+                                        "Too many states in a single query.");
+
+        if (strv_length(patterns) > MANAGER_MAX_PATTERNS_PER_CALL)
+                return sd_bus_error_set(reterr_error, SD_BUS_ERROR_LIMITS_EXCEEDED,
+                                        "Too many patterns in a single query.");
+
         r = mac_selinux_access_check(message, "status", reterr_error);
         if (r < 0)
                 return r;
diff --git a/src/core/manager.h b/src/core/manager.h
index abf1764d78..9afc70b39a 100644
--- a/src/core/manager.h
+++ b/src/core/manager.h
@@ -14,9 +14,13 @@
 
 struct libmnt_monitor;
 
-/* Enforce upper limit how many names we allow */
+/* Enforce upper limit on how many names we allow */
 #define MANAGER_MAX_NAMES 131072 /* 128K */
 
+/* Enforce upper limit on the number of patterns/states requested over IPC */
+#define MANAGER_MAX_PATTERNS_PER_CALL 4096U
+#define MANAGER_MAX_STATES_PER_CALL 256U
+
 /* On sigrtmin+18, private commands */
 enum {
         MANAGER_SIGNAL_COMMAND_DUMP_JOBS = _COMMON_SIGNAL_COMMAND_PRIVATE_BASE + 0,
diff --git a/src/libsystemd/sd-json/json-util.h b/src/libsystemd/sd-json/json-util.h
index 34d79d5238..cea2d368b4 100644
--- a/src/libsystemd/sd-json/json-util.h
+++ b/src/libsystemd/sd-json/json-util.h
@@ -9,8 +9,6 @@
 #include "sd-forward.h"
 #include "string-util.h"        /* IWYU pragma: keep */
 
-#define ENVIRONMENT_ASSIGNMENTS_MAX 1024U
-
 #define JSON_VARIANT_REPLACE(v, q)        \
         do {                              \
                 typeof(v)* _v = &(v);     \
diff --git a/src/machine/machine-dbus.c b/src/machine/machine-dbus.c
index a9d15ca5f7..28f64b3c9b 100644
--- a/src/machine/machine-dbus.c
+++ b/src/machine/machine-dbus.c
@@ -435,6 +435,10 @@ int bus_machine_method_open_shell(sd_bus_message *message, void *userdata, sd_bu
         r = sd_bus_message_read_strv(message, &env);
         if (r < 0)
                 return r;
+
+        if (strv_length(env) > ENVIRONMENT_ASSIGNMENTS_MAX)
+                return sd_bus_error_set(error, SD_BUS_ERROR_LIMITS_EXCEEDED,
+                                        "Too many environment assignments in a single query.");
         if (!strv_env_is_valid(env))
                 return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid environment assignments");