# CVE-2026-40909: WWBN AVideo has a Path Traversal in Locale Save Endpoint Enables Arbitrary PHP File Write to Any Web-Accessible Directory (RCE)

> An attacker can exploit a path traversal vulnerability in the locale save endpoint to write arbitrary PHP files, achieving remote code execution.

- **Severity:** High 8.7 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Apr 2026
- **Updated:** 21 Apr 2026
- **Also known as:** GHSA-6rc6-p838-686f

## What is CVE-2026-40909?

CVE-2026-40909 is a high-severity path traversal vulnerability in Wwbn Avideo, published on 21 Apr 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

WWBN AVideo is an open source video platform. In versions 29.0 and prior, the locale save endpoint (`locale/save.php`) constructs a file path by directly concatenating `$_POST['flag']` into the path at line 30 without any sanitization. The `$_POST['code']` parameter is then written verbatim to that path via `fwrite()` at line 40. An admin attacker (or any user who can CSRF an admin, since no CSRF token is checked and cookies use `SameSite=None`) can traverse out of the `locale/` directory and write arbitrary `.php` files to any writable location on the filesystem, achieving Remote Code Execution. Commit 57f89ffbc27d37c9d9dd727212334846e78ac21a fixes the issue.

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

## Which versions are affected by CVE-2026-40909?

2 open source packages ship an affected version, including wwbn/avideo. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `wwbn/avideo` | Packagist | All versions to 29.0 | None |
| `wwbn/avideo` | Packagist | All versions to 29.0 | None |

Products: Wwbn Avideo.

## How do I fix CVE-2026-40909?

No fix has been published for CVE-2026-40909 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-40909 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40909 exists.

## Other vulnerabilities in Wwbn Avideo

- [CVE-2026-40911](https://insights.sbomify.com/CVE-2026-40911/): WWBN AVideo YPTSocket WebSocket Broadcast Relay Leads to Unauthenticated Cross-User JavaScript Execution via Client-Side eval() Sinks (critical 10.0)
- [CVE-2026-33478](https://insights.sbomify.com/CVE-2026-33478/): AVideo Multi-Chain Attack: Unauthenticated Remote Code Execution via Clone Key Disclosure, Database Dump, and Command Injection (critical 10.0)
- [CVE-2022-30534](https://insights.sbomify.com/CVE-2022-30534/): Command injection in AVideo (critical 9.9)
- [CVE-2022-30547](https://insights.sbomify.com/CVE-2022-30547/): Path traversal in AVideo (critical 9.9)
- [CVE-2022-32572](https://insights.sbomify.com/CVE-2022-32572/): Command injection in AVideo (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40909 and fix it if it is affected.

What it is: CVE-2026-40909 is a high-severity path traversal vulnerability in Wwbn Avideo, published on 21 Apr 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40909 exists.

Affected packages and fixed versions:
- wwbn/avideo (Packagist): affected all versions up to 29.0; no fix listed
- wwbn/avideo (Packagist): affected all versions up to 29.0; no fix listed

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-2026-40909/ (Markdown: https://insights.sbomify.com/CVE-2026-40909/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40909
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40909
- OSV: https://osv.dev/vulnerability/CVE-2026-40909

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40909/
Summaries are generated and may contain mistakes; the official description above is the record.