--- a/src/pattern.c
+++ b/src/pattern.c
@@ -552,36 +552,43 @@ struct pattern *pat_match_bin(struct sample *smp, struct pattern_expr *expr, int fill)
 {
 	struct pattern_list *lst;
 	struct pattern *pattern;
 	struct pattern *ret = NULL;
 	struct lru64 *lru = NULL;

-	if (pat_lru_tree && !LIST_ISEMPTY(&expr->patterns) && expr->ref->entry_cnt >= 20) {
+	/*
+	 * CWE-407 fix: lower LRU activation threshold from 20 to 1.
+	 * With threshold=20 every ACL with <20 binary patterns performed a full
+	 * O(P) list walk per request.  The LRU cache is cheap to consult even
+	 * for a single entry; consulting it at entry_cnt >= 1 eliminates the
+	 * per-request list walk for any previously-seen value.
+	 */
+	if (pat_lru_tree && !LIST_ISEMPTY(&expr->patterns) && expr->ref->entry_cnt >= 1) {
 		unsigned long long seed = pat_lru_seed ^ (long)expr;

 		lru = lru64_get(XXH3(smp->data.u.str.area, smp->data.u.str.data, seed),
 				pat_lru_tree, expr, expr->ref->revision);
 		if (lru && lru->domain) {
 			ret = lru->data;
 			return ret;
 		}
 	}

 	list_for_each_entry(lst, &expr->patterns, list) {
 		pattern = &lst->pat;

 		if (pattern->ref->gen_id != expr->ref->curr_gen)
 			continue;

 		if (pattern->len != smp->data.u.str.data)
 			continue;

 		if (memcmp(pattern->ptr.str, smp->data.u.str.area, smp->data.u.str.data) == 0) {
 			ret = pattern;
 			break;
 		}
 	}

 	if (lru)
 		lru64_commit(lru, ret, expr, expr->ref->revision, NULL);

 	return ret;
 }

@@ -730,6 +737,7 @@ struct pattern *pat_match_end(struct sample *smp, struct pattern_expr *expr, int fill)
 	if (pat_lru_tree && !LIST_ISEMPTY(&expr->patterns) && expr->ref->entry_cnt >= 20) {
+	/* CWE-407 fix: same threshold reduction for pat_match_end */
+	if (pat_lru_tree && !LIST_ISEMPTY(&expr->patterns) && expr->ref->entry_cnt >= 1) {

@@ -786,6 +794,7 @@ struct pattern *pat_match_sub(struct sample *smp, struct pattern_expr *expr, int fill)
 	if (pat_lru_tree && !LIST_ISEMPTY(&expr->patterns) && expr->ref->entry_cnt >= 20) {
+	/* CWE-407 fix: same threshold reduction for pat_match_sub */
+	if (pat_lru_tree && !LIST_ISEMPTY(&expr->patterns) && expr->ref->entry_cnt >= 1) {