CVE-2026-87091: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in uscnanbu Welcart e-Commerce
The Welcart e-Commerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Settlement Notification Parameters in all versions up to, and including, 2.12.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The IPN endpoint accepts the 'rel' and 'option' parameters with no authentication, nonce validation, or signature verification, meaning any unauthenticated attacker can directly submit malicious payloads that are stored and later rendered in the administrator's settlement error log view.
AI Analysis
Technical Summary
CVE-2026-87091 describes a stored cross-site scripting vulnerability in the Welcart e-Commerce WordPress plugin. The vulnerability arises from insufficient input sanitization and output escaping of the 'rel' and 'option' parameters in the IPN endpoint. Because this endpoint does not require authentication, nonce validation, or signature verification, unauthenticated attackers can submit malicious payloads that are stored and later executed in the administrator's settlement error log view. This vulnerability affects all versions up to and including 2.12.2.
Potential Impact
An unauthenticated attacker can inject arbitrary web scripts that execute in the context of the administrator's browser when viewing the settlement error log. This can lead to confidentiality and integrity loss, such as theft of administrator credentials or session tokens, or manipulation of administrative functions. Availability impact is not indicated.
Mitigation Recommendations
No official patch or fix is currently documented. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to the settlement error log view to trusted administrators only and consider implementing web application firewall rules to detect and block malicious payloads targeting the 'rel' and 'option' parameters.
CVE-2026-87091: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in uscnanbu Welcart e-Commerce
Description
The Welcart e-Commerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Settlement Notification Parameters in all versions up to, and including, 2.12.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The IPN endpoint accepts the 'rel' and 'option' parameters with no authentication, nonce validation, or signature verification, meaning any unauthenticated attacker can directly submit malicious payloads that are stored and later rendered in the administrator's settlement error log view.
CVSS v3.1
Score 7.2high
Affected software
uscnanbu
Welcart e-Commerce
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-87091 describes a stored cross-site scripting vulnerability in the Welcart e-Commerce WordPress plugin. The vulnerability arises from insufficient input sanitization and output escaping of the 'rel' and 'option' parameters in the IPN endpoint. Because this endpoint does not require authentication, nonce validation, or signature verification, unauthenticated attackers can submit malicious payloads that are stored and later executed in the administrator's settlement error log view. This vulnerability affects all versions up to and including 2.12.2.
Potential Impact
An unauthenticated attacker can inject arbitrary web scripts that execute in the context of the administrator's browser when viewing the settlement error log. This can lead to confidentiality and integrity loss, such as theft of administrator credentials or session tokens, or manipulation of administrative functions. Availability impact is not indicated.
Mitigation Recommendations
No official patch or fix is currently documented. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to the settlement error log view to trusted administrators only and consider implementing web application firewall rules to detect and block malicious payloads targeting the 'rel' and 'option' parameters.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Wordfence
- Date Reserved
- 2026-09-08T20:03:43.422Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ac096c0a43b0b3b89a12233
Added to database: 10/03/2026, 05:46:40 UTC
Last enriched: 10/03/2026, 06:01:36 UTC
Last updated: 10/04/2026, 02:46:42 UTC
Views: 14
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