diff --git a/Source/Core/Core/NetPlayClient.cpp b/Source/Core/Core/NetPlayClient.cpp
index 8c38fc0b53..20edd35c0e 100644
--- a/Source/Core/Core/NetPlayClient.cpp
+++ b/Source/Core/Core/NetPlayClient.cpp
@@ -1211,7 +1211,7 @@ void NetPlayClient::OnSyncSaveDataWii(sf::Packet& packet)
     for (u8& byte : header.md5)
       packet >> byte;
     packet >> header.unk2;
-    for (size_t i = 0; i < header.banner_size; i++)
+    for (size_t i = 0; i < std::min<size_t>(header.banner_size, sizeof(header.banner)); i++)
       packet >> header.banner[i];
 
     // BkHeader
diff --git a/Source/Core/Core/NetPlayCommon.cpp b/Source/Core/Core/NetPlayCommon.cpp
index f1a580cf09..89ec2864a1 100644
--- a/Source/Core/Core/NetPlayCommon.cpp
+++ b/Source/Core/Core/NetPlayCommon.cpp
@@ -197,6 +197,12 @@ bool DecompressPacketIntoFile(sf::Packet& packet, const std::string& file_path)
     if (!cur_len)
       break;  // We reached the end of the data stream
 
+    if (cur_len > in_buffer.size())
+    {
+      PanicAlertFmt("LZO error - input is too large");
+      return false;
+    }
+
     for (size_t j = 0; j < cur_len; j++)
     {
       packet >> in_buffer[j];
@@ -281,6 +287,12 @@ std::optional<std::vector<u8>> DecompressPacketIntoBuffer(sf::Packet& packet)
     if (!cur_len)
       break;  // We reached the end of the data stream
 
+    if (cur_len > in_buffer.size())
+    {
+      PanicAlertFmt("LZO error - input is too large");
+      return {};
+    }
+
     for (size_t j = 0; j < cur_len; j++)
     {
       packet >> in_buffer[j];
diff --git a/Source/Core/Core/NetPlayServer.cpp b/Source/Core/Core/NetPlayServer.cpp
index 57cd691060..8f6ba17368 100644
--- a/Source/Core/Core/NetPlayServer.cpp
+++ b/Source/Core/Core/NetPlayServer.cpp
@@ -1976,7 +1976,7 @@ bool NetPlayServer::SyncSaveData(const SaveSyncInfo& sync_info)
         for (u8 byte : header->md5)
           pac << byte;
         pac << header->unk2;
-        for (size_t i = 0; i < header->banner_size; i++)
+        for (size_t i = 0; i < std::min<size_t>(header->banner_size, sizeof(header->banner)); i++)
           pac << header->banner[i];
 
         // BkHeader