# CVE-2026-104478: Formwork before 2.3.13 Path Traversal via BackupController Download and Delete

> Authenticated users can read or delete arbitrary files via path traversal in the backup controller, bypassing basename checks.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Oct 2026
- **Updated:** 5 Oct 2026
- **Also known as:** GHSA-4v26-phwj-4v5r

## What is CVE-2026-104478?

CVE-2026-104478 is a high-severity path traversal vulnerability in getformwork formwork, published on 2 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Formwork before 2.3.13 contains a path traversal vulnerability in BackupController that allows authenticated panel users to read or delete arbitrary files. Attackers with backup download or delete permission can supply a base64-encoded backslash-separated traversal payload that bypasses PHP basename on Linux to access files outside the backup directory.

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

## Which versions are affected by CVE-2026-104478?


## How do I fix CVE-2026-104478?

No fix has been published for CVE-2026-104478 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-104478 being exploited?

There is no known exploitation of CVE-2026-104478 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-104478 and fix it if it is affected.

What it is: CVE-2026-104478 is a high-severity path traversal vulnerability in getformwork formwork, published on 2 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-104478 in the wild and no public exploit code.

Affected product: getformwork formwork. 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-2026-104478/ (Markdown: https://insights.sbomify.com/CVE-2026-104478/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-104478
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104478
- OSV: https://osv.dev/vulnerability/CVE-2026-104478

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-104478/
Summaries are generated and may contain mistakes; the official description above is the record.