PT-2026-3882 · Microsoft+4 · Office Excel+4

Ling101W · Published 2026-01-21 · Updated 2026-02-27 · CVE-2026-23873

Positive Technologies (AI Summary)

CVSS v3.1

9.0

Critical

Base vector

AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions hustoj (affected versions not specified)

Description hustoj is an open source online judge system built on PHP/C++/MySQL/Linux. The application is susceptible to CSV Injection (Formula Injection) through the contest rank export functionality, specifically in the contestrank.xls.php and admin/ranklist export.php files. The system does not properly sanitize user-provided input, particularly the Nickname field, before including it in exported .xls files. An attacker can exploit this by setting their nickname to an Excel formula. When an administrator opens the exported rank list in Microsoft Excel, the malicious formula will execute, potentially leading to arbitrary command execution (RCE) on the administrator’s machine or data exfiltration.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

RCE

Weakness Enumeration

CWE-1236

Related Identifiers

CVE-2026-23873

GHSA-GQWV-V7VX-2QJW

Affected Products

Linux

Office Excel

Mysql Server

Php

Hustoj

References · 8

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23873.json · Exploit
• https://github.com/zhblue/hustoj/security/advisories/GHSA-gqwv-v7vx-2qjw · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-23873 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-23873 · Security Note
• https://t.me/cveNotify/149496 · Telegram Post
• https://t.me/cveNotify/153507 · Telegram Post
• https://twitter.com/CVEnew/status/2014125836195054057 · Twitter Post
• https://twitter.com/lsof/status/2014398978926731299 · Twitter Post