# CVE-2026-24479: HUSTOJ has Arbitrary File Write (Zip Slip) in Problem Import Modules that leads to RCE

> Attackers can achieve remote code execution by uploading a malicious ZIP archive with path traversal sequences in HUSTOJ problem import modules.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Jan 2026
- **Updated:** 27 Jan 2026
- **Also known as:** GHSA-xmgg-2rw4-7fxj

## What is CVE-2026-24479?

CVE-2026-24479 is a critical path traversal vulnerability in zhblue hustoj, published on 27 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

HUSTOF is an open source online judge based on PHP/C++/MySQL/Linux for ACM/ICPC and NOIP training. Prior to version 26.01.24, the problem_import_qduoj.php and problem_import_hoj.php modules fail to properly sanitize filenames within uploaded ZIP archives. Attackers can craft a malicious ZIP file containing files with path traversal sequences (e.g., ../../shell.php). When extracted by the server, this allows writing files to arbitrary locations in the web root, leading to Remote Code Execution (RCE). Version 26.01.24 contains a fix for the issue.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-24479?

It affects 1 product.


Products: Hustoj Hustoj.

## How do I fix CVE-2026-24479?

No fix has been published for CVE-2026-24479 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-24479 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-24479 exists.

Public exploit code:

- HUSTOJ Admin users can zip-slip problem_import_qduoj.php, planting PHP files in webroot for RCE (metasploit)
- HUSTOJ Zip-Slip v26.01.24 -  RCE (exploitdb)

## Other vulnerabilities in zhblue hustoj

- [CVE-2025-50938](https://insights.sbomify.com/CVE-2025-50938/): Cross-site scripting in n/a (medium 6.1)
- [CVE-2022-42187](https://insights.sbomify.com/CVE-2022-42187/): Cross-site scripting in n/a (medium 6.1)
- [CVE-2026-23873](https://insights.sbomify.com/CVE-2026-23873/): HUSTOJ is Vulnerable to Stored CSV Injection (Formula Injection) in Contest Rank Export (medium 5.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-24479 and fix it if it is affected.

What it is: CVE-2026-24479 is a critical path traversal vulnerability in zhblue hustoj, published on 27 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-24479 exists.

Affected product: zhblue hustoj. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-24479/ (Markdown: https://insights.sbomify.com/CVE-2026-24479/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-24479
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-24479
- OSV: https://osv.dev/vulnerability/CVE-2026-24479

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-24479/
Summaries are generated and may contain mistakes; the official description above is the record.