Payment Gateway for PayPal Pro, PayPal…: Insufficient Verification of Data Authenticity
CVE-2026-127204 is a high-severity insufficient verification of data authenticity vulnerability in Payment Gateway for PayPal Pro, PayPal Checkout & Subscriptions for WooCommerce from Wp.insider, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 4.1.1 as the first without the flaw, so updating Payment Gateway for PayPal Pro, PayPal Checkout & Subscriptions for WooCommerce to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.18% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Payment Gateway for PayPal Pro, PayPal Checkout & Subscriptions for WooCommerce to 4.1.1 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Wp.insider | Payment Gateway for PayPal Pro, PayPal Checkout & Subscriptions for WooCommerce | before 4.1.1 | 4.1.1 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 7.5 | High | CNA (vulncheck.com) |
Official description
WooCommerce PayPal Pro Payment Gateway plugin before 4.1.1 contains an unauthenticated payment bypass vulnerability that allows remote attackers to mark unpaid orders as paid by exploiting the pp_capture_order AJAX handler, which is gated only by a public checkout nonce and fails to properly validate the PayPal capture response status. Attackers can supply a valid _paypal_order_id to trigger payment_complete() without verifying the capture status or amount, causing the store to fulfill goods or services that were never paid for and resulting in direct financial loss to the merchant.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Insufficient Verification of Data Authenticity
The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.
More Insufficient Verification of Data Authenticity vulnerabilities (CWE-345)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Insufficient Verification of Data Authenticity vulnerabilities
- 7.5 High severity
- 8.8 High severity
- 8.8 High severity
- 9.6 Critical severity
- 8.9 High severity
- 10.0 Critical severity
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