CVE-2026-103329

Super Payments <= 1.43.0 - Payment Verification Bypass to Unauthenticated Arbitrary Order Payment Forgery

2026-10-07 00:00

Strategic Overview

Status: Patched in 1.43.1
Affected Plugin: Super Payments – WooCommerce Payment Gateway
Affected Version: <= 1.43.0
CVSS: 5.3Medium
Weakness type: CWE-602 · Client-Side Enforcement of Server-Side Security
CVE: CVE-2026-103329

View all Super Payments – WooCommerce Payment Gateway vulnerabilities

At a glance

CVE-2026-103329 is a medium-severity Client-Side Enforcement of Server-Side Security vulnerability in the Super Payments WordPress plugin, affecting versions <= 1.43.0. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 1.43.1; sites on affected versions should update now. Disclosed October 2026, reported by Naoki Kawahigashi.

Vulnerability Overview

The Super Payments plugin for WordPress is vulnerable to Payment Verification Bypass in all versions up to, and including, 1.43.0. This is due to missing rejection of an empty signing key in the webhook signature verification logic, allowing anyone to compute a valid HMAC with an empty secret. This makes it possible for unauthenticated attackers to mark arbitrary WooCommerce orders as paid without making a payment, by forging a valid webhook signature using an empty signing key.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user.

CWE-602: Client-Side Enforcement of Server-Side Security

The product is composed of a server that relies on the client to implement a mechanism that is intended to protect the server.

Remediation

Update to version 1.43.1, or a newer patched version

How does WordSec protect against this?

This one needs no account at all, which puts it outside what login hardening can reach; WordSec's login security narrows the account-level paths around it, and the firewall is what inspects the request itself. None of that substitutes for the fix: Super Payments 1.43.1 closes this, and updating the plugin is the step that ends it.

Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-103329 https://www.wordfence.com/threat-intel/vulnerabilities/id/5835aed6-510c-4241-b957-462a400e3fa9 https://nvd.nist.gov/vuln/detail/CVE-2026-103329

CVSS Vector

5.3

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityLow
AvailabilityNone

This record contains material that is subject to copyright

CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.

https://www.cve.org/Legal/TermsOfUse

Defiant hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute this software vulnerability information. Any copy of the software vulnerability information you make for such purposes is authorized provided that you include a hyperlink to this vulnerability record and reproduce Defiant's copyright designation and this license in any such copy.

https://www.wordfence.com/wordfence-intelligence-terms-and-conditions/