CVE-2026-103688
Tenable Plugin
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AI Threat Summary
CVE-2026-103688 is a critical vulnerability with a CVSS score of 9.8 affecting the target software. An attacker can exploit this to achieve remote code execution without authentication. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.
Description
The Checkout Files Upload for WooCommerce WordPress plugin before 2.4.0 does not validate uploaded file types when its accepted file types setting is left empty, which it documents as the way to accept all files, allowing unauthenticated users to upload arbitrary files, including PHP files that lead to remote code execution on servers that execute PHP from the uploads directory.
Attack Chain
Attacker identifies vulnerable service instances using Shodan, Censys, or active scanning
Attacker crafts malicious payload exploiting CVE-2026-103688 to achieve remote code execution
Attacker executes arbitrary OS commands or shellcode in the context of the vulnerable process
Attacker installs backdoor, cron job, or web shell for persistent access
Attacker uses compromised host as pivot point to access internal network resources
MITRE ATT&CK Techniques
Attacker exploits the vulnerability in an internet-facing service to gain initial access
Post-exploitation shell commands executed through the vulnerability
Attacker downloads malware or tools after gaining code execution
Indicators of Compromise
| Type | Value | Description | |
|---|---|---|---|
| user_agent | Mozilla/5.0 (compatible; exploit/1.0) |
Generic exploit scanner user agent pattern | |
| url | /api/vuln-endpoint?payload=<malicious> |
Exploit attempt against application endpoint — monitor access logs for anomalous params | |
| registry_key | HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\backdoor |
Persistence mechanism after successful RCE |
Remediation
Quick Facts
| CVE ID | CVE-2026-103688 |
| CVSS Score | 9.8 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Published | 2026-10-28 |
| Exploited | No |
| CISA KEV | No |
| PoC | Available |