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21Track

Unauthenticated arbitrary file upload in Contact Manager

kleor Contact Manager · CVE-2026-109218 ETK-2026-2837 EUVD-2026-111608 GHSA-GFC3-VP5H-PP8W
0 news outlets0 CERTs and agencies1 research labs

Assessment: Track

SSVC decision points: exploitation none, automatable yes, technical impact total, deployment low.

What is it?

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.

Evidence

Technical advisories1Detailed write-ups from security research teams

Exploitation

  • Exploit code published (not verified by us)
  • Exploited in the wild (confirmed by a source)
  • Listed as known exploited (CISA KEV)
CVSS
9.8
EPSS
–
First seen
2 h ago
Status
corroborated

All kleor vulnerabilities