YITH WooCommerce Gift Cards < 4.38.1 - Unauthenticated Gift Card Balance Double-Spending via Race Condition

The YITH WooCommerce Gift Cards WordPress plugin before 4.38.1 does not lock or atomically update a gift card's balance when it is redeemed at checkout, allowing an attacker who holds a gift card code to spend more than its funded value by submitting multiple checkouts for the same code at the same time.