diff --git a/Common/Net/HTTPHeaders.cpp b/Common/Net/HTTPHeaders.cpp
index 410ed63060..afa04b6a88 100644
--- a/Common/Net/HTTPHeaders.cpp
+++ b/Common/Net/HTTPHeaders.cpp
@@ -31,6 +31,11 @@ bool RequestHeader::GetParamValue(const char *param_name, std::string *value) co
 	for (size_t i = 0; i < v.size(); i++) {
 		std::vector<std::string_view> parts;
 		SplitString(v[i], '=', parts);
+		if (parts.size() < 2) {
+			// A parameter with no '=' at all, like "?foo". SplitString hands back a single element
+			// for that, so parts[1] would be reading off the end of the vector.
+			continue;
+		}
 		DEBUG_LOG(Log::HTTP, "Param: %.*s Value: %.*s", (int)parts[0].size(), parts[0].data(), (int)parts[1].size(), parts[1].data());
 		if (parts[0] == param_name) {
 			*value = parts[1];
diff --git a/Common/Net/Sinks.cpp b/Common/Net/Sinks.cpp
index 2325fb2b19..194c605a3f 100644
--- a/Common/Net/Sinks.cpp
+++ b/Common/Net/Sinks.cpp
@@ -358,6 +358,10 @@ bool OutputSink::Printf(const char *fmt, ...) {
 }
 
 bool OutputSink::Block() {
+	if (hasError_) {
+		// A broken socket reports as ready forever, so waiting on it would just spin.
+		return false;
+	}
 	if (!fd_util::WaitUntilReady((int)fd_, 5.0, true)) {
 		return false;
 	}
diff --git a/Common/Net/WebsocketServer.cpp b/Common/Net/WebsocketServer.cpp
index 5a3f31a25d..d017711c84 100644
--- a/Common/Net/WebsocketServer.cpp
+++ b/Common/Net/WebsocketServer.cpp
@@ -400,9 +400,10 @@ bool WebSocketServer::ReadFrame() {
 			return false;
 
 		mask = &header[10];
-		// Read from big endian.
-		uint64_t high = (header[2] << 24) | (header[3] << 16) | (header[4] << 8) | (header[5] << 0);
-		uint64_t low = (header[6] << 24) | (header[7] << 16) | (header[8] << 8) | (header[9] << 0);
+		// Read from big endian. Cast first: these promote to int, so a byte >= 0x80 in the top
+		// position would shift into the sign bit and then sign-extend into the u64.
+		uint64_t high = ((uint64_t)header[2] << 24) | ((uint64_t)header[3] << 16) | ((uint64_t)header[4] << 8) | (uint64_t)header[5];
+		uint64_t low = ((uint64_t)header[6] << 24) | ((uint64_t)header[7] << 16) | ((uint64_t)header[8] << 8) | (uint64_t)header[9];
 		sz = (high << 32) | low;
 
 		if ((sz & 0x8000000000000000ULL) != 0) {