SSRF in Qingdaou Onlinejudge
CVE-2026-5538
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
EPSS: 0.002 (10.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.
Affected products
- Qingdaou Onlinejudge — versions 1.6.0, 1.6.1
Weakness classification (CWE)
References
- cna@vuldb.com (technical-description, vdb-entry)
- cna@vuldb.com (signature, permissions-required)
- cna@vuldb.com (third-party-advisory)
- cna@vuldb.com (issue-tracking)
Frequently asked questions
- What is CVE-2026-5538?
- CVE-2026-5538 is a medium-severity vulnerability in Qingdaou Onlinejudge, classified under Server-Side Request Forgery (SSRF). CVSS score: 6.3/10. Published 2026-04-05.
- How severe is CVE-2026-5538?
- Medium severity. CVSS v3 base score is 6.3 out of 10.