XSS in Uscnanbu Welcart E-Commerce

CVE-2026-87091

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published .

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-87091?
CVE-2026-87091 is a high-severity vulnerability in Uscnanbu Welcart E-Commerce, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-10-03.
How severe is CVE-2026-87091?
High severity. CVSS v3 base score is 7.2 out of 10.