Joomla Extension - j2commerce.com - Stored XSS in Guest checkout in J2Store 1.0.0-3.3.20, 4.0.0-4.0.20, 4.1.0-4.1.5 - J2Commerce 4.1.5 is vulnerable to Stored Cross-Site Scripting (XSS) through the guest checkout billing address fields. An unauthenticated attacker exploits a filter bypass in Joomla's Input::getArray() combined with PHP's variables_order=EGPCS (Cookie overrides POST in $_REQUEST ) to store unsanitized HTML in fields such as billing_first_name.
Published: 2026-08-21
Updated: 2026-08-21
Base Score: 3.5
Vector: CVSS2#AV:N/AC:M/Au:S/C:N/I:P/A:N
Severity: Low
Base Score: 5.4
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
Base Score: 8.6
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00335