Security readout for executives and security teams
Plain-English summary
HUSTOJ contest rank exports can carry spreadsheet formulas hidden in user nicknames. If an administrator exports rankings and opens the file in Microsoft Excel, Excel may run the formula. The advisory says this could affect the administrator’s workstation, including data theft or command execution. No fix was available when published.
Executive priority
Prioritize if HUSTOJ is internet-facing or used with untrusted participants. The server vulnerability is medium severity, but the business risk centers on compromise of administrator workstations through exported files.
Technical view
CVE-2026-23873 is stored CSV/formula injection in HUSTOJ contest rank export paths contestrank.xls.php and admin/ranklist_export.php. User-controlled Nickname values are not sanitized before being included in an .xls export rendered as an HTML table. A low-privileged user can plant formula content; exploitation requires an administrator to export and open the file in Excel.
Likely exposure
Organizations running zhblue HUSTOJ versions up to and including 26.01.01 are affected. Exposure is highest where untrusted users can set nicknames and administrators routinely export contest rankings to Excel.
Exploitation context
No active exploitation is reported in the provided sources, and the CVE is not listed as KEV. Exploitation requires attacker account access to set a nickname and administrator interaction with the exported rank file in Microsoft Excel.
Researcher notes
The public advisory states all versions through 26.01.01 are vulnerable and no fix was available at publication. Evidence supports stored formula injection, not direct server-side RCE. Avoid treating this as remotely exploitable without user interaction.
Mitigation direction
- Check the GitHub advisory and vendor project for updated guidance or a fixed release.
- Avoid opening HUSTOJ rank exports in Excel until mitigated.
- Limit who can change nicknames or participate in contests requiring admin exports.
- Treat exported ranking files as untrusted content.
- Review administrative workflows for unnecessary spreadsheet export use.
Validation and detection
- Inventory HUSTOJ deployments and identify versions at or below 26.01.01.
- Confirm whether contestrank.xls.php and admin/ranklist_export.php are present and used.
- Review whether Nickname values are sanitized before export.
- Determine whether administrators open rank exports in Microsoft Excel.
- Monitor vendor advisory updates for patch availability.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CWE-1236: Exact CWE lookup
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Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-23873 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.2 (4.0)
- Known Exploited
- No
- Published
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
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
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——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
5.2MediumVector: 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
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/zhblue/hustoj/security/advisories/GHSA-gqwv-v7vx-2qjwCVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Formula Elements in a CSV File
Improper Neutralization of Formula Elements in a CSV File represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.