diff --git a/src/network/kernel/qdnslookup_unix.cpp b/src/network/kernel/qdnslookup_unix.cpp
index 6cdd4e3adfd..bb13dcbdf06 100644
--- a/src/network/kernel/qdnslookup_unix.cpp
+++ b/src/network/kernel/qdnslookup_unix.cpp
@@ -356,6 +356,8 @@ void QDnsLookupRunnable::query(QDnsLookupReply *reply)
                 return reply->makeInvalidReplyError(QDnsLookup::tr("Invalid mail exchange record"));
             reply->mailExchangeRecords.append(record);
         } else if (type == QDnsLookup::SRV) {
+            if (size < 7)
+                return reply->makeInvalidReplyError(QDnsLookup::tr("Invalid service record"));
             const quint16 priority = qFromBigEndian<quint16>(response + offset);
             const quint16 weight = qFromBigEndian<quint16>(response + offset + 2);
             const quint16 port = qFromBigEndian<quint16>(response + offset + 4);