hustoj is an open source online judge based on PHP/C++/MySQL/Linux for ACM/ICPC and NOIP training. All versions are vulnerable to CSV Injection (Formula Injection) through the contest rank export functionality (contestrank.xls.php and admin/ranklist_export.php). The application fails to sanitize user-supplied input (specifically the "Nickname" field) before exporting it to an .xls file (which renders as an HTML table but is opened by Excel). If a malicious user sets their nickname to an Excel formula when an administrator exports and opens the rank list in Microsoft Excel, the formula will be executed. This can lead to arbitrary command execution (RCE) on the administrator's machine or data exfiltration. A fix was not available at the time of publication.
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Fixes

Solution

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Workaround

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History

Wed, 21 Jan 2026 23:45:00 +0000

Type Values Removed Values Added
Description hustoj is an open source online judge based on PHP/C++/MySQL/Linux for ACM/ICPC and NOIP training. All versions are vulnerable to CSV Injection (Formula Injection) through the contest rank export functionality (contestrank.xls.php and admin/ranklist_export.php). The application fails to sanitize user-supplied input (specifically the "Nickname" field) before exporting it to an .xls file (which renders as an HTML table but is opened by Excel). If a malicious user sets their nickname to an Excel formula when an administrator exports and opens the rank list in Microsoft Excel, the formula will be executed. This can lead to arbitrary command execution (RCE) on the administrator's machine or data exfiltration. A fix was not available at the time of publication.
Title HUSTOJ is Vulnerable to Stored CSV Injection (Formula Injection) in Contest Rank Export
Weaknesses CWE-1236
References
Metrics cvssV4_0

{'score': 5.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-01-21T23:26:21.924Z

Reserved: 2026-01-16T21:02:02.899Z

Link: CVE-2026-23873

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-01-22T00:15:51.770

Modified: 2026-01-22T00:15:51.770

Link: CVE-2026-23873

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses