CVE-2026-109218: kleor Contact Manager (Critical, CVSS 9.8)
- CVSS
- 9.8 Critical (v3.1)
- EPSS
- 0.6% chance of exploitation in the next 30 days (higher than 50.6% of CVEs)
- Exploited in the wild
- Not on CISA’s KEV list
- Public exploit
- None reported in public exploit databases
- Weakness
- CWE-434
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Published
- Oct 28, 2026
What it is
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.
Description from the National Vulnerability Database.
What to do
Check whether you run kleor Contact Manager, then apply the vendor’s fix or mitigation from the advisories below.
Sources: NVD, FIRST EPSS, CISA KEV, and public exploit databases (availability only). ThreatRoundup reports whether public exploit code exists but never links to it: fake proof-of-concepts that infect security researchers are common. This page updates automatically.