diff --git a/source/src/serveractions.h b/source/src/serveractions.h
index 2b2e1419..5c263200 100644
--- a/source/src/serveractions.h
+++ b/source/src/serveractions.h
@@ -65,13 +65,22 @@ struct mapaction : serveraction
             bool notify = valid_client(caller);
             int maploc = MAP_NOTFOUND;
             mapstats *ms = map[0] ? getservermapstats(map, false, &maploc) : NULL;
-            mapok = (ms != NULL) && ( (mode != GMODE_COOPEDIT && mapisok(ms)) || (mode == GMODE_COOPEDIT && !readonlymap(maploc)) );
+            bool validname = validmapname(map);
+            mapok = (ms != NULL) && validname && ( (mode != GMODE_COOPEDIT && mapisok(ms)) || (mode == GMODE_COOPEDIT && !readonlymap(maploc)) );
             if(!mapok)
             {
-                if(notify) sendservmsg(ms ?
-                    ( mode == GMODE_COOPEDIT ? "this map cannot be coopedited in this server" : "sorry, but this map does not satisfy some quality requisites to be played in MultiPlayer Mode" ) :
-                    "the server does not have this map",
-                    caller);
+                if(notify)
+                {
+                    if(!validname)
+                        sendservmsg("invalid map name", caller);
+                    else
+                    {
+                        sendservmsg(ms ?
+                            ( mode == GMODE_COOPEDIT ? "this map cannot be coopedited in this server" : "sorry, but this map does not satisfy some quality requisites to be played in MultiPlayer Mode" ) :
+                            "the server does not have this map",
+                            caller);
+                    }
+                }
             }
             else
             { // check, if map supports mode
diff --git a/source/src/tools.h b/source/src/tools.h
index 0fe897cf..78ead339 100644
--- a/source/src/tools.h
+++ b/source/src/tools.h
@@ -160,6 +160,18 @@ inline bool issimilar (char s, char d)
     return false;
 }
 
+#define MAXMAPNAMELEN 64
+inline bool validmapname(char *s)
+{
+    if(strlen(s) > MAXMAPNAMELEN) return false;
+    while(*s != '\0') 
+    {
+        if(!isalnum(*s) && *s != '_' && *s != '-') return false;
+        ++s;
+    }
+    return true;
+}
+
 inline bool findpattern (char *s, char *d) // returns true if there is more than 80% of similarity
 {
     int len, hit = 0;
diff --git a/source/src/worldio.cpp b/source/src/worldio.cpp
index fc3e8da4..2db74b9f 100644
--- a/source/src/worldio.cpp
+++ b/source/src/worldio.cpp
@@ -10,11 +10,11 @@ void backup(char *name, char *backupname)
     rename(findfile(name, "wb"), backupfile);
 }
 
-static string cgzname, ocgzname, bakname, pcfname, mcfname, omcfname;
+static string cgzname, ocgzname, bakname, pcfname, mcfname, omcfname, mapname;
 
 const char *setnames(const char *name)
 {
-    string pakname, mapname;
+    string pakname;
     const char *slash = strpbrk(name, "/\\");
     if(slash)
     {
@@ -205,6 +205,11 @@ void save_world(char *mname)
 {
     if(!*mname) mname = getclientmap();
     if(securemapcheck(mname)) return;
+    if(!validmapname(mname))
+    {
+        conoutf("\f3invalid map name. it must only contains letters, digits, '-', '_' and be less than %d characters long", MAXMAPNAMELEN);
+        return;
+    }
     voptimize();
     toptimize();
     setnames(mname);
@@ -322,6 +327,11 @@ bool load_world(char *mname)        // still supports all map formats that have
         copystring(mcfname, omcfname);
     }
     else maploaded = getfilesize(cgzname);
+    if(!validmapname(mapname))
+    {
+        conoutf("\f3invalid map name. it must only contains letters, digits, '-', '_' and be less than %d characters long", MAXMAPNAMELEN);
+        return false;
+    }
     stream *f = opengzfile(cgzname, "rb");
     if(!f) { conoutf("\f3could not read map %s", cgzname); return false; }
     header tmp;