CVE-2026-89418 google-protobuf contains an unbounded recursion when parsing unknown protobuf group fields

Description

google-protobuf contains an unbounded recursion when parsing unknown protobuf group fields. An attacker can send a small crafted payload of deeply nested START_GROUP wire bytes to any Node.js service that calls the generated deserializeBinary() API, causing a RangeError: Maximum call stack size exceeded and crashing the process. No authentication or prior knowledge of the schema is required.

Affected products and versions