CVE-2026-16621
Payment Gateway for PayPal on WooCommerce < 9.2.1 - Unauthenticated Payment Bypass via PayPal Advanced Return Handler
Description
The Payment Gateway for PayPal on WooCommerce WordPress plugin before 9.2.1 does not verify that payment actually succeeded before completing an order in its PayPal return handler: it reads attacker-controlled parameters, performs no amount comparison and no order-ownership check, and completes the order even when the server-side gateway verification fails, allowing an unauthenticated attacker to mark arbitrary orders as paid without paying.
INFO
Published Date :
Aug. 12, 2026, 12:17 p.m.
Last Modified :
Aug. 12, 2026, 1:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-16621
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the WooCommerce PayPal Payments plugin to version 9.2.1.
- Verify payment success before completing orders.
- Implement proper order ownership checks.
- Validate attacker-controlled parameters carefully.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-16621.
| URL | Resource |
|---|---|
| https://wpscan.com/vulnerability/76c4cff2-1166-45fe-9517-5eda2d24c35d/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-16621 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-16621
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-16621 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-16621 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 12, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-16621', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-12T12:14:12.062302Z'} -
New CVE Received by [email protected]
Aug. 12, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Unknown', 'product': 'Payment Gateway for PayPal on WooCommerce', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '9.2.1', 'versionType': 'semver'}], 'collectionURL': 'https://wordpress.org/plugins', 'defaultStatus': 'unaffected'}] Added Description The Payment Gateway for PayPal on WooCommerce WordPress plugin before 9.2.1 does not verify that payment actually succeeded before completing an order in its PayPal return handler: it reads attacker-controlled parameters, performs no amount comparison and no order-ownership check, and completes the order even when the server-side gateway verification fails, allowing an unauthenticated attacker to mark arbitrary orders as paid without paying. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Added Reference https://wpscan.com/vulnerability/76c4cff2-1166-45fe-9517-5eda2d24c35d/