# UNDF: UNDF-2026-000000187
--- a/service_scan.h
+++ b/service_scan.h
@@ -280,8 +280,8 @@ class ServiceProbe {
  std::vector<ServiceProbeMatch *> matches; // first-ever use of STL in Nmap!
  char *fallbackStr;
  ServiceProbe *fallbacks[MAXFALLBACKS+1];
-  std::vector<u16> probableports;
-  std::vector<u16> probablesslports;
-  std::vector<const char *> detectedServices;
+  std::unordered_set<u16> probableports;
+  std::unordered_set<u16> probablesslports;
+  std::unordered_set<std::string> detectedServices;

--- a/service_scan.cc
+++ b/service_scan.cc
@@ -1,6 +1,7 @@
 #include "service_scan.h"
+#include <unordered_set>

@@ -1215,7 +1215,7 @@ void ServiceProbe::setPortVector(std::vector<u16> *portv, const char *portstr,
     /* Now I have a rangestart and a rangeend, so I can add these ports */
     while(rangestart <= rangeend) {
-      portv->push_back(rangestart);
+      portv->insert(rangestart);
       rangestart++;
     }

@@ -1254,10 +1254,9 @@ bool ServiceProbe::portIsProbable(enum service_tunnel_type tunnel, u16 portno) c
   const std::vector<u16> *portv;
-
   portv = (tunnel == SERVICE_TUNNEL_SSL)? &probablesslports : &probableports;
-
-  if (find(portv->begin(), portv->end(), portno) == portv->end())
+  if (portv->find(portno) == portv->end())
     return false;
   return true;
 }

@@ -1266,10 +1266,8 @@ bool ServiceProbe::serviceIsPossible(const char *sname) const {
-  std::vector<const char *>::const_iterator vi;
-
-  for(vi = detectedServices.begin(); vi != detectedServices.end(); vi++) {
-    if (strcmp(*vi, sname) == 0)
-      return true;
-  }
-  return false;
+  return detectedServices.count(sname) > 0;
 }

@@ -1301,7 +1301,7 @@ void ServiceProbe::addService(const char *sname) {
-    detectedServices.push_back(sname);
+    detectedServices.insert(sname);
 }