diff --git a/plugins/elanfp/fu-elanfp-firmware.c b/plugins/elanfp/fu-elanfp-firmware.c
index 64d2b8bbd..38d66cdf7 100644
--- a/plugins/elanfp/fu-elanfp-firmware.c
+++ b/plugins/elanfp/fu-elanfp-firmware.c
@@ -52,6 +52,7 @@ fu_elanfp_firmware_parse(FuFirmware *firmware,
 	gsize bufsz;
 	guint32 tag = 0;
 	gsize offset = 0x00;
+	guint img_cnt = 0;
 
 	/* check the tag */
 	buf = g_bytes_get_data(fw, &bufsz);
@@ -80,6 +81,15 @@ fu_elanfp_firmware_parse(FuFirmware *firmware,
 		g_autoptr(GBytes) blob = NULL;
 		g_autoptr(FuFirmware) img = NULL;
 
+		/* check sanity */
+		if (img_cnt++ > 256) {
+			g_set_error_literal(error,
+					    FWUPD_ERROR,
+					    FWUPD_ERROR_NOT_SUPPORTED,
+					    "too many images detected");
+			return FALSE;
+		}
+
 		/* type, reserved, start-addr, len */
 		if (!fu_common_read_uint32_safe(buf,
 						bufsz,
@@ -89,6 +99,17 @@ fu_elanfp_firmware_parse(FuFirmware *firmware,
 						error))
 			return FALSE;
 
+		/* check not already added */
+		img = fu_firmware_get_image_by_idx(firmware, fwtype, NULL);
+		if (img != NULL) {
+			g_set_error(error,
+				    FWUPD_ERROR,
+				    FWUPD_ERROR_NOT_SUPPORTED,
+				    "already parsed image with fwtype 0x%x",
+				    fwtype);
+			return FALSE;
+		}
+
 		/* done */
 		if (fwtype == FU_ELANTP_FIRMWARE_IDX_END)
 			break;
@@ -121,6 +142,14 @@ fu_elanfp_firmware_parse(FuFirmware *firmware,
 						G_LITTLE_ENDIAN,
 						error))
 			return FALSE;
+		if (length == 0) {
+			g_set_error(error,
+				    FWUPD_ERROR,
+				    FWUPD_ERROR_NOT_SUPPORTED,
+				    "zero size fwtype 0x%x not supported",
+				    fwtype);
+			return FALSE;
+		}
 		blob = fu_common_bytes_new_offset(fw, start_addr, length, error);
 		if (blob == NULL)
 			return FALSE;