CVE-2026-5538 | QingdaoU OnlineJudge up to 1.6.1 judge_server_heartbeat Endpoint JudgeServer.service_url server-side request forgery

A vulnerability described as critical has been identified in QingdaoU OnlineJudge up to 1.6.1. Affected by this issue is the function service_url of the file JudgeServer.service_url of the component judge_server_heartbeat Endpoint. The manipulation results in server-side request forgery.

This vulnerability is known as CVE-2026-5538. It is possible to launch the attack remotely. No exploit is available.

The vendor was contacted early about this disclosure but did not respond in any way.