CVE-2026-72545: OpenSignLabs OpenSign - Insecure Direct Object Reference

An insecure direct object reference vulnerability in OpenSignLabs OpenSign through 2.37.0 allows unauthenticated remote attackers to write to any contact record via the updatecontacttour Parse cloud function. The function performs no authentication or authorization before updating the target contact record. An attacker can corrupt or overwrite contact data for any user in the system without credentials.