Contact Manager WordPress plugin: Unauthenticated arbitrary file upload
Summary
The Contact Manager plugin for WordPress, up to and including version 9.1.2, contains an arbitrary file upload flaw in the add_message function. A blacklist bypass using a trailing dot in the filename lets unauthenticated attackers upload files that may be executable. Remote code execution is only possible under specific conditions, including Apache with libapache2-mod-php and a timing window before the uploaded file is deleted.
Affected
- kleor Contact Manager WordPress plugin, all versions up to and including 9.1.2
Fixed in
- Version 9.1.3 (likely fix according to the WordPress.org changelog; verify against the changeset before closing)
Workaround
- No vendor workaround known.
- If the update is delayed, deactivate and remove the plugin.
- Review the WordPress uploads directory for unexpected script files.
Exploitation
- Exploited in the wild: not known.
- CISA KEV status: not listed according to a third-party aggregator; the CISA catalog was not checked directly.
- Public proof of concept: none found in the research, but this was not exhaustive.
Our recommendation
- Update the Contact Manager plugin to version 9.1.3 or later as a priority.
- Check whether any websites use the plugin, including client sites.
- On internet-facing sites that ran 9.1.2 or earlier, check the uploads directory for unexpected files and signs of compromise.
- Monitor web server logs for requests to uploaded files.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Wordfence threat intelligence record www.wordfence.com
- Contact Manager 9.1.2 add-message.php plugins.trac.wordpress.org
- Trac changeset 9.1.2 to 9.1.3 plugins.trac.wordpress.org
- WordPress.org plugin page (changelog) wordpress.org
- VulDB entry vuldb.com
- OffSeq radar entry radar.offseq.com
- Strix CVE entry www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 30 Oct 2026, 16:17.
Original description (NVD)
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.
NVD references (7)
- https://fr.wordpress.org/plugins/contact-manager/
- https://plugins.trac.wordpress.org/browser/contact-manager/tags/9.1.2/contact-manager.php#L42
- https://plugins.trac.wordpress.org/browser/contact-manager/tags/9.1.2/includes/add-message.php#L254
- https://plugins.trac.wordpress.org/browser/contact-manager/tags/9.1.2/includes/add-message.php#L256
- https://plugins.trac.wordpress.org/browser/contact-manager/tags/9.1.2/includes/forms/processing.php#L102
- https://plugins.trac.wordpress.org/changeset?reponame=&new=3767815%40contact-manager%2Ftags%2F9.1.3&old=36611…
- https://www.wordfence.com/threat-intel/vulnerabilities/id/b359ef59-4c2e-4d4e-b000-1845525131de?source=cve
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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