diff --git a/src/drivers/gnss/septentrio/sbf/decoder.cpp b/src/drivers/gnss/septentrio/sbf/decoder.cpp
index 33f180a159..14e0682074 100644
--- a/src/drivers/gnss/septentrio/sbf/decoder.cpp
+++ b/src/drivers/gnss/septentrio/sbf/decoder.cpp
@@ -118,6 +118,7 @@ int Decoder::parse(Header *header) const
 int Decoder::parse(DOP *message) const
 {
 	if (can_parse() && id() == BlockID::DOP) {
+		static_assert(sizeof(*message) <= sizeof(_message.payload), "Buffer too small");
 		memcpy(message, _message.payload, sizeof(DOP));
 		return PX4_OK;
 	}
@@ -128,6 +129,7 @@ int Decoder::parse(DOP *message) const
 int Decoder::parse(PVTGeodetic *message) const
 {
 	if (can_parse() && id() == BlockID::PVTGeodetic) {
+		static_assert(sizeof(*message) <= sizeof(_message.payload), "Buffer too small");
 		memcpy(message, _message.payload, sizeof(PVTGeodetic));
 		return PX4_OK;
 	}
@@ -138,6 +140,7 @@ int Decoder::parse(PVTGeodetic *message) const
 int Decoder::parse(ReceiverStatus *message) const
 {
 	if (can_parse() && id() == BlockID::ReceiverStatus) {
+		static_assert(sizeof(*message) <= sizeof(_message.payload), "Buffer too small");
 		memcpy(message, _message.payload, sizeof(ReceiverStatus));
 		return PX4_OK;
 	}
@@ -148,6 +151,7 @@ int Decoder::parse(ReceiverStatus *message) const
 int Decoder::parse(QualityInd *message) const
 {
 	if (can_parse() && id() == BlockID::QualityInd) {
+		static_assert(sizeof(*message) <= sizeof(_message.payload), "Buffer too small");
 		// Safe to copy entire size of the message as it is smaller than the maximum expected SBF message size.
 		// It's up to the user of the parsed message to ignore the invalid fields.
 		memcpy(message, _message.payload, sizeof(QualityInd));
@@ -160,11 +164,16 @@ int Decoder::parse(QualityInd *message) const
 int Decoder::parse(RFStatus *message) const
 {
 	if (can_parse() && id() == BlockID::PVTGeodetic) {
+		static_assert(sizeof(*message) <= sizeof(_message.payload), "Buffer too small");
 		memcpy(message, _message.payload, sizeof(RFStatus) - sizeof(RFStatus::rf_band));
 
 		for (uint8_t i = 0; i < math::min(message->n, k_max_rfband_blocks); i++) {
-			memcpy(&message->rf_band[i], &_message.payload[sizeof(RFStatus) - sizeof(RFStatus::rf_band) + i *
-					message->sb_length], sizeof(RFBand));
+			const unsigned offset = sizeof(RFStatus) - sizeof(RFStatus::rf_band) + i *
+						message->sb_length;
+
+			if (offset + sizeof(RFBand) <= sizeof(_message.payload)) {
+				memcpy(&message->rf_band[i], &_message.payload[offset], sizeof(RFBand));
+			}
 		}
 
 		return PX4_OK;
@@ -176,6 +185,7 @@ int Decoder::parse(RFStatus *message) const
 int Decoder::parse(GALAuthStatus *message) const
 {
 	if (can_parse() && id() == BlockID::GALAuthStatus) {
+		static_assert(sizeof(*message) <= sizeof(_message.payload), "Buffer too small");
 		memcpy(message, _message.payload, sizeof(GALAuthStatus));
 		return PX4_OK;
 	}
@@ -186,6 +196,7 @@ int Decoder::parse(GALAuthStatus *message) const
 int Decoder::parse(VelCovGeodetic *message) const
 {
 	if (can_parse() && id() == BlockID::VelCovGeodetic) {
+		static_assert(sizeof(*message) <= sizeof(_message.payload), "Buffer too small");
 		memcpy(message, _message.payload, sizeof(VelCovGeodetic));
 		return PX4_OK;
 	}
@@ -196,11 +207,17 @@ int Decoder::parse(VelCovGeodetic *message) const
 int Decoder::parse(GEOIonoDelay *message) const
 {
 	if (can_parse() && id() == BlockID::GEOIonoDelay) {
+		static_assert(sizeof(*message) <= sizeof(_message.payload), "Buffer too small");
 		memcpy(message, _message.payload, sizeof(GEOIonoDelay) - sizeof(GEOIonoDelay::idc));
 
-		for (size_t i = 0; i < math::min(message->n, (uint8_t)4); i++) {
-			memcpy(&message->idc[i], &_message.payload[sizeof(GEOIonoDelay) - sizeof(GEOIonoDelay::idc) + i *
-					message->sb_length], sizeof(IDC));
+		for (size_t i = 0; i < math::min(message->n, (uint8_t)(sizeof(GEOIonoDelay::idc) / sizeof(GEOIonoDelay::idc[0])));
+		     i++) {
+			const unsigned offset = sizeof(GEOIonoDelay) - sizeof(GEOIonoDelay::idc) + i *
+						message->sb_length;
+
+			if (offset + sizeof(IDC) <= sizeof(_message.payload)) {
+				memcpy(&message->idc[i], &_message.payload[offset], sizeof(IDC));
+			}
 		}
 
 		return PX4_OK;
@@ -212,6 +229,7 @@ int Decoder::parse(GEOIonoDelay *message) const
 int Decoder::parse(AttEuler *message) const
 {
 	if (can_parse() && id() == BlockID::AttEuler) {
+		static_assert(sizeof(*message) <= sizeof(_message.payload), "Buffer too small");
 		memcpy(message, _message.payload, sizeof(AttEuler));
 		return PX4_OK;
 	}
@@ -222,6 +240,7 @@ int Decoder::parse(AttEuler *message) const
 int Decoder::parse(AttCovEuler *message) const
 {
 	if (can_parse() && id() == BlockID::AttCovEuler) {
+		static_assert(sizeof(*message) <= sizeof(_message.payload), "Buffer too small");
 		memcpy(message, _message.payload, sizeof(AttCovEuler));
 		return PX4_OK;
 	}