CVE-2026-80311 in Stripe Payment Forms by WP Full Pay Plugin
Summary
by MITRE • 08/29/2026
The Stripe Payment Forms by WP Full Pay WordPress plugin before 8.5.5 does not verify that a subscription belongs to the customer bound to the requesting customer-portal session before cancelling it, allowing a user with a confirmed portal session to cancel subscriptions belonging to other customers.
Exploitation requires the attacker to know the target subscription's identifier, which is high-entropy and not enumerable through the Stripe Payment Forms by WP Full Pay WordPress plugin before 8.5.5.
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Analysis
by VulDB Data Team • 08/29/2026
The vulnerability identified in versions of the Stripe Payment Forms by WP Full Pay WordPress plugin prior to version 8.5.5 represents a critical failure in access control logic, specifically categorized under CWE-639: Authorization Bypass Through User-Controlled Key. This flaw arises from an insufficient verification mechanism within the subscription cancellation workflow. When a user initiates a session through the Stripe Customer Portal, the plugin is responsible for ensuring that any actions taken during this session are strictly bound to the specific customer identity associated with that portal instance. However, the implementation fails to validate whether the subscription identifier being targeted for cancellation actually belongs to the authenticated customer whose session is active. This architectural oversight allows an attacker who has successfully established a valid Customer Portal session to manipulate the request payload by substituting the target subscription ID with one belonging to another user.
From an operational perspective, this vulnerability enables unauthorized account manipulation and data integrity violations. An adversary can exploit this flaw to cancel subscriptions that they do not own, potentially causing financial loss for other customers or disrupting service continuity for legitimate users. While the exploitation of this vulnerability requires knowledge of a high-entropy subscription identifier, which is generally difficult to guess through brute force, it does not require complex enumeration techniques if such identifiers are exposed elsewhere in the application interface, leaked via logs, or obtained through side-channel attacks. The presence of valid session tokens combined with predictable or accessible resource IDs creates a significant risk vector for unauthorized state changes within the payment processing ecosystem managed by the plugin.
This issue aligns closely with MITRE ATT&CK technique T1078: Valid Accounts, as it relies on the use of legitimate authentication credentials to perform actions outside their intended scope. It also reflects principles found in CWE-269: Improper Privilege Management, where a user is able to execute functions that exceed their assigned privileges due to flawed logic rather than a lack of permissions at the system level. The core issue lies not in the authentication mechanism itself but in the authorization layer's failure to enforce object-level security controls effectively.
To mitigate this vulnerability, immediate updates to version 8.5.5 or later are required, as these versions implement proper validation checks that bind subscription actions to the specific customer ID associated with the active session token. In addition to upgrading, administrators should ensure that their WordPress environment is hardened against information disclosure vulnerabilities that might expose high-entropy identifiers such as Stripe subscription IDs. Implementing strict server-side validation for all resource ownership before processing state-changing requests like cancellations or modifications is essential. Developers must adhere to secure coding practices that verify the relationship between the authenticated user and every resource they attempt to modify, ensuring that authorization checks are performed consistently across all endpoints exposed by the plugin.