{"data":{"id":"CVE-2026-77999","cve_id":"CVE-2026-77999","title":"Unauthenticated PayPal callback forgery leading to order confirmation fraud in J2Store 1.0.0-3.3.21, 4.0.0-4.0.21, 4.1.0-4.1.6","summary":"Unauthenticated PayPal callback forgery leading to order confirmation fraud in J2Store 1.0.0-3.3.21, 4.0.0-4.0.21, 4.1.0-4.1.6","severity":"HIGH","cvss":{"score":8.7,"version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","source":"nvd"},"published_at":"2026-09-03T13:06:08.760000Z","modified_at":"2026-09-03T17:30:37.197000Z","withdrawn_at":null,"is_joomla":true,"is_joomla_core":false,"relevance":"certain","product":"Extension Joomla — j2commerce.com","extension":{"type":null,"name":null},"sources":["nvd"],"source_count":1,"url":"https://cve.oyer.fr/cve/CVE-2026-77999","description":"Joomla Extension - j2commerce.com - Unauthenticated PayPal callback forgery leading to order confirmation fraud in J2Store 1.0.0-3.3.21, 4.0.0-4.0.21, 4.1.0-4.1.6 - The PayPal IPN listener's signature check (`_validateIPN()`) accepted `UNVERIFIED` and any non-`INVALID` response as valid, made its verification request with `CURLOPT_SSL_VERIFYPEER` disabled, and stored its verdict in a field nothing downstream ever checked — so processing continued regardless of the outcome. Separately, the paid-amount comparison only ran when `mc_gross` was a positive number; omitting the field from the POST body (`floatval(null) == 0`) skipped the check entirely. Combined with a merchant-configured `receiver_email` and a sequential, enumerable order id read from the `custom` field, an anonymous POST was enough to move a pending order straight to `CONFIRMED` with no payment, or force another customer's pending order to `FAILED`. `paypalv2.php` performed no amount check under any circumstances.","cwe":["CWE-472","CWE-602"],"affected":[{"package":null,"product":"J2Store extension for Joomla","vendor":"j2commerce.com","ecosystem":null,"cpe":null,"version_start":"1.0.0","version_end":"3.3.21","version_end_inclusive":true,"fixed_version":null,"type":null,"source":"nvd"},{"package":null,"product":"J2Store extension for Joomla","vendor":"j2commerce.com","ecosystem":null,"cpe":null,"version_start":"4.0.0","version_end":"4.0.21","version_end_inclusive":true,"fixed_version":null,"type":null,"source":"nvd"},{"package":null,"product":"J2Store extension for Joomla","vendor":"j2commerce.com","ecosystem":null,"cpe":null,"version_start":"4.1.0","version_end":"4.1.6","version_end_inclusive":true,"fixed_version":null,"type":null,"source":"nvd"}],"references":[{"url":"https://www.j2commerce.com/","title":null,"source":"nvd"}],"source_records":[{"source":"nvd","external_id":"CVE-2026-77999","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-77999","severity":"HIGH","cvss_score":8.7,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_version":"4.0","first_seen_at":"2026-09-26T09:34:34.485817Z","last_seen_at":"2026-09-26T09:34:34.485817Z"}],"history":[{"at":"2026-09-26T09:34:34.485817Z","event":"created","source":"nvd","detail":"Détectée via nvd"}]}}