Anton Extensions WordPress plugin: Unauthenticated arbitrary file upload leading to RCE
Summary
The Anton Extensions WordPress plugin up to and including version 1.2.2 performs no capability check, nonce verification or file-type validation before writing attacker-supplied content to an attacker-chosen path. An unauthenticated remote attacker can upload arbitrary PHP files and execute code on the web server. No user interaction is required, and the flaw is reachable on any internet-facing WordPress site where the plugin is active.
Affected
- Anton Extensions WordPress plugin (slug 4nton-extensions), versions 0 to 1.2.2 inclusive
- Vendor and developer: Unknown
Fixed in
- Unverified: VulDB names version 1.2.3 as a fix, but this is not confirmed by the vendor or a vendor advisory.
- WPScan lists 'No known fix'.
Workaround
- Remove or deactivate the plugin until an official fix is verified.
- If uploads are not strictly required, disable file uploads in the WordPress media settings.
- A web application firewall rule blocking PHP uploads may act as a temporary stopgap, but it is generic and not vendor-supplied.
Exploitation
- CISA SSVC: Exploitation 'none', Automatable 'yes', Technical Impact 'total'.
- Not listed in CISA KEV. No known in-the-wild exploitation is recorded.
- A public proof-of-concept entry may exist (WPScan and Vulners); not verified. Assume a working exploit may be available.
- EPSS is low (reported as 0.21% by one source), which does not reduce the risk for an unauthenticated RCE.
Our recommendation
- Inventory all WordPress sites and check whether the Anton Extensions plugin is installed.
- Deactivate and remove the plugin on all affected sites now.
- Review the web root for unexpected or recently modified PHP files and check web server logs for unusual requests.
- If you reinstall, first verify the fixed version with the developer or the wordpress.org changelog.
- Treat any site running this plugin as potentially compromised until checked.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- WPScan vulnerability record wpscan.com
- VulDB CVE-2026-104028 vuldb.com
- OpenCVE CVE-2026-104028 app.opencve.io
- Vulners NVD mirror CVE-2026-104028 vulners.com
- GitHub alert (EPSS, KEV) github.com
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, 19:18.
Original description (NVD)
The Anton Extensions WordPress plugin through 1.2.2 does not perform any capability check, nonce verification, or file-type validation before writing attacker-supplied content to an attacker-chosen path, allowing unauthenticated attackers to upload arbitrary PHP files and achieve remote code execution.
NVD references (1)
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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