# CVE-2026-74239: XenForo < 2.3.13 Path Traversal via Style Archive Importer on Windows

> Authenticated administrators can achieve remote code execution via path traversal in the style archive importer on Windows deployments.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 8 Sep 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-fxw8-p3x8-7xqx

## What is CVE-2026-74239?

CVE-2026-74239 is a high-severity path traversal vulnerability in XenForo, published on 8 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

XenForo before 2.3.13 contains a path traversal vulnerability in the style archive importer on Windows deployments that allows authenticated non-super administrators with style permissions to write arbitrary files outside the intended extraction directory by using backslash-based traversal sequences in ZIP member names. Attackers can craft a malicious ZIP archive with backslash path separators that bypass forward-slash validation to write arbitrary bytes to any web-server-writable path, including the public web root, achieving persistent code execution as the web-server account.

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

## Which versions are affected by CVE-2026-74239?

It affects 1 product.


Products: Xenforo Xenforo.

## How do I fix CVE-2026-74239?

No fix has been published for CVE-2026-74239 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-74239 being exploited?

There is no known exploitation of CVE-2026-74239 in the wild and no public exploit code.

Public exploit code:

- Sanitized XenForo write-up and proof of concept for CVE-2026-74239. (github_poc): https://github.com/BomboBombone/CVE-2026-74239

## Other vulnerabilities in XenForo

- [CVE-2025-71279](https://insights.sbomify.com/CVE-2025-71279/): XenForo Passkey Security Bypass (critical 9.3)
- [CVE-2026-73309](https://insights.sbomify.com/CVE-2026-73309/): XenForo < 2.3.13 Authentication Bypass via OAuth2 Token Endpoint (critical 9.1)
- [CVE-2026-73311](https://insights.sbomify.com/CVE-2026-73311/): XenForo < 2.3.13 OAuth2 Authorization Code Reuse (critical 9.1)
- [CVE-2026-73312](https://insights.sbomify.com/CVE-2026-73312/): XenForo < 2.3.13 Refresh Token Replay via Expired Access Token (critical 9.1)
- [CVE-2024-38457](https://insights.sbomify.com/CVE-2024-38457/): Xenforo before 2.2.16 allows CSRF. (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74239 and fix it if it is affected.

What it is: CVE-2026-74239 is a high-severity path traversal vulnerability in XenForo, published on 8 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-74239 in the wild and no public exploit code.

Affected product: XenForo. 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-2026-74239/ (Markdown: https://insights.sbomify.com/CVE-2026-74239/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74239
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74239
- OSV: https://osv.dev/vulnerability/CVE-2026-74239

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74239/
Summaries are generated and may contain mistakes; the official description above is the record.