Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-4001 is a critical-severity Eval Injection (CWE-95) vulnerability in Acowebs (inferred from references). Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique JavaScript (T1059.007); ranked in the top 50% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-4001 is a remote code execution vulnerability in the Woocommerce Custom Product Addons Pro plugin for WordPress, affecting all versions up to and including 5.4.1. The flaw exists in the process_custom_formula() function within includes/process/price.php, where user-submitted field values for custom pricing formulas are passed directly to PHP's eval() function without adequate sanitization or validation. The plugin's sanitize_values() method only strips HTML tags but does not escape single quotes or block PHP code injection, enabling attackers to inject and execute arbitrary code.
Unauthenticated attackers can exploit this vulnerability remotely with low complexity and no user interaction required. By submitting a specially crafted value to a WCPA text field configured for custom pricing (pricingType: "custom" with {this.value}), they can trigger the unsafe eval() execution. Successful exploitation grants full control over the server, including high confidentiality, integrity, and availability impacts, as reflected in the CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) and mapped to CWE-95 (Improper Neutralization of Directives in Dynamically Evaluated Code).
Mitigation guidance is available in advisories from the plugin vendor at https://acowebs.com/woo-custom-product-addons/ and Wordfence at https://www.wordfence.com/threat-intel/vulnerabilities/id/70a2b6ff-defc-4722-9af9-3cae94e98632?source=cve.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-14652
Vulnerability Data
The Woocommerce Custom Product Addons Pro plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 5.4.1 via the custom pricing formula eval() in the process_custom_formula() function within includes/process/price.php. This is due to insufficient…
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sanitization and validation of user-submitted field values before passing them to PHP's eval() function. The sanitize_values() method strips HTML tags but does not escape single quotes or prevent PHP code injection. This makes it possible for unauthenticated attackers to execute arbitrary code on the server by submitting a crafted value to a WCPA text field configured with custom pricing formula (pricingType: "custom" with {this.value}).
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.3.2
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and code analysis can discover eval-injection flaws but does not stop their introduction.
Input validation explicitly requires neutralizing untrusted data before it reaches dynamic evaluation constructs such as eval.
Secure-development standards and tools can mandate safe coding patterns that avoid unsafe dynamic evaluation.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require input neutralization and avoidance of unsafe dynamic evaluation.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect eval injection vulnerabilities before deployment.
Secure development life cycle mandates input validation and safe coding practices that directly prevent eval injection.
Application security requirements include rules against dynamic code execution of untrusted input.
Secure architecture principles discourage unsafe dynamic evaluation constructs.
Secure coding explicitly requires neutralization of input before dynamic evaluation, directly mitigating eval injection.
Separation of environments limits the blast radius if eval injection occurs in non-production.