CVE-2026-109218 Contact Manager <= 9.1.2 - Unauthenticated Arbitrary File Upload via Trailing-Dot Filename Blacklist Bypass
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-109218?
CVE-2026-109218 is a critical vulnerability in kleor Contact Manager, published on 28 Oct 2026.
Official description
The Contact Manager plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 9.1.2 via the add_message function. This is due to an incomplete extension blacklist that fails to detect dangerous extensions when a trailing dot causes the extension-derivation routine to return an empty string, which sanitize_file_name() then silently removes before the file is written to disk. This makes it possible for unauthenticated attackers to upload files that may be executable, which makes remote code execution possible. Successful code execution additionally requires the server to use Apache with libapache2-mod-php (which maps .phar to PHP by default) and the attacker to retrieve the uploaded file within the brief window before it is removed by unlink() at end of request.
Weakness: CWE-434
Which versions are affected by CVE-2026-109218?
How do I fix CVE-2026-109218?
No fix has been published for CVE-2026-109218 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-109218 being exploited?
There is no known exploitation of CVE-2026-109218 in the wild and no public exploit code.
Sources
Also known as GHSA-gfc3-vp5h-pp8w.