medusajs/medusa

A race condition vulnerability exists in MedusaJS Medusa v2.12.2 and earlier in the registerUsage() function of the promotion module. The function performs a non-atomic read-check-update operation when enforcing promotion usage limits. This allows unauthenticated remote attackers to bypass usage limits by sending concurrent checkout requests, resulting in unlimited redemptions of limited-use promotional codes and potential financial loss.