diff --git a/apache2/re.c b/apache2/re.c
index d067c68419..943d9b6810 100644
--- a/apache2/re.c
+++ b/apache2/re.c
@@ -986,6 +986,47 @@ msre_action *msre_create_action(msre_engine *engine, apr_pool_t *mp, const char
     return action;
 }
 
+/** 
+ * Helper function for action_exists. It checks if "name=value" is present in table for supplied action.
+ */
+static int apr_table_action_exists(apr_pool_t* p, const apr_table_t* vartable, const char* action, const char* name, const char* value) {
+    if (strcmp(name, action) != 0) return 0;
+
+    const char* vars = apr_table_getm(p, vartable, name);
+    if (!vars) return 0;
+
+    char pattern[200];
+    apr_snprintf(pattern, sizeof(pattern), "(?:^|,)%.185s(?:,|$)", value);
+
+    char* error_msg = NULL;
+    msc_regex_t* regex = msc_pregcomp(p, pattern, 0, NULL, NULL);
+    if (regex == NULL) return 0;
+
+    return (msc_regexec(regex, vars, strlen(vars), &error_msg) >= 0);
+}
+
+/**
+ * Checks if "name=value" is present in table for tags, logdata (and others).
+ */
+static int action_exists(apr_pool_t* p, const apr_table_t* vartable, const char* name, const char* value) {
+    /* logdata & msg cannot be used because ',' is used as entries separators */
+    if (apr_table_action_exists(p, vartable, "capture", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "chain", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "initcol", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "multiMatch", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "phase", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "sanitizeArg", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "sanitizeMatched", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "sanitizeMatchedBytes", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "sanitizeRequestHeader", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "sanitizeResponseHeader", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "setrsc", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "setsid", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "setuid", name, value)) return 1;
+    if (apr_table_action_exists(p, vartable, "tag", name, value)) return 1;
+	return 0;
+}
+
 /**
  * Generic parser that is used as basis for target and action parsing.
  * It breaks up the input string into name-parameter pairs and places
@@ -1103,9 +1144,11 @@ int msre_parse_generic(apr_pool_t *mp, const char *text, apr_table_t *vartable,
             value = apr_pstrmemdup(mp, value, p - value);
         }
 
-        /* add to table */
-        apr_table_addn(vartable, name, value);
-        count++;
+        /* add to table (only if not already present) */
+        if (!action_exists(mp, vartable, name, value)) {
+			apr_table_addn(vartable, name, value);
+			count++;
+		}
 
         /* move to the first character of the next name-value pair */
         while(isspace(*p)||(*p == ',')||(*p == '|')) p++;