CVE-2026-5538: QingdaoU OnlineJudge judge_server_heartbeat Endpoint JudgeServer.service_url server-side request forgery

Severity: medium (CVSS 6.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-05 · updated 2026-07-24
Weakness: CWE-918

Description

A vulnerability was detected 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. It is possible to launch the attack remotely. The vendor was contacted early about this disclosure but did not respond in any way.

Affected products

QingdaoU OnlineJudge: 1.6.0, 1.6.1

References

https://github.com/AnalogyC0de/public_exp/issues/27
https://vuldb.com/submit/782203
https://vuldb.com/vuln/355291
https://vuldb.com/vuln/355291/cti

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