RCE in Acowebs Woocommerce Custom Product Addons Pro

CVE-2026-4001

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 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}).

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.010 (61.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 61st percentile — 61.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-4001: held from 0.007 to 0.010.

EPSS over last 30 days · oldest: 0.007 · newest: 0.010 · change: +0.003

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-4001?
CVE-2026-4001 is a critical-severity vulnerability in Acowebs Woocommerce Custom Product Addons Pro, classified under Eval Injection. CVSS score: 9.8/10. Published 2026-03-24.
How severe is CVE-2026-4001?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2026-4001 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.