diff --git a/php857-streambucket-soap-rce-rpoc/scripts/validate.sh b/php857-streambucket-soap-rce-rpoc/scripts/validate.sh
new file mode 100644
index 0000000..7167824
--- /dev/null
+++ b/php857-streambucket-soap-rce-rpoc/scripts/validate.sh
@@ -0,0 +1,26 @@
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+PHP_BIN="${PHP_BIN:-${1:-}}"
+POC="$ROOT/poc/rpoc.php"
+LOG="$ROOT/evidence/local-validation.txt"
+
+if [[ -z "$PHP_BIN" ]]; then
+  echo "usage: PHP_BIN=/path/to/php scripts/validate.sh"
+  echo "usage: scripts/validate.sh /path/to/php"
+  exit 2
+fi
+
+mkdir -p "$ROOT/evidence"
+"$PHP_BIN" -n "$POC" | tee "$LOG"
+
+MARKER_PATH="$(awk -F= '/^marker_path=/{print $2; exit}' "$LOG")"
+if [[ -z "$MARKER_PATH" || ! -f "$MARKER_PATH" ]]; then
+  echo "marker_check=missing" | tee -a "$LOG"
+  exit 1
+fi
+
+MARKER_CONTENT="$(cat "$MARKER_PATH")"
+echo "marker_check=present" | tee -a "$LOG"
+echo "marker_content=$MARKER_CONTENT" | tee -a "$LOG"
+[[ "$MARKER_CONTENT" == "PHP857_RCE" ]]