CVE-2026-40909

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 classification

• CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Primary references

• security-advisories@github.com — Patch
• security-advisories@github.com — Exploit, Vendor Advisory
• 134c704f-9b21-4f2e-91b3-4a467353bcc0 — Exploit, Vendor Advisory