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

High 8.7 Published Updated

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

Exploited in the wild
Not known
Login needed
An administrator
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

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

Which versions are affected by CVE-2026-40909?

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

PackageAffectedFixed in
wwbn/avideo PackagistAll versions to 29.0None
wwbn/avideo PackagistAll versions to 29.0None

Products include 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.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-40909 being exploited?

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

All Wwbn Avideo vulnerabilities

Sources

Also known as GHSA-6rc6-p838-686f.

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