Joomla Extension - j2commerce.com - Unescaped request data reflected into PayPal notify redirect in J2Store 1.0.0-3.3.2, 4.0.0-4.0.22, 4.1.0-4.1.7

published 2026-09-15 54 d ago modified 2026-09-16 53 d ago also EUVD-2026-79290

cvss: 5.3; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 39%
public exploits: 0; none known

Joomla Extension - j2commerce.com - Unescaped request data reflected into PayPal notify redirect in J2Store 1.0.0-3.3.2, 4.0.0-4.0.22, 4.1.0-4.1.7 - A crafted link to the paypal notify endpoint, if followed by a victim's browser (or an automated system that fetches it), causes the resulting redirect to `com_j2store`'s checkout controller to carry attacker-chosen query parameters instead of only the intended `view=checkout&task=confirmPayment&orderpayment_type=...&paction=process` set — parameter injection/smuggling into that follow-up request. This requires a victim to load the crafted link (`UI:R`/`UI:P`); it does not by itself grant an unauthenticated attacker anything they could not already obtain by requesting the target `com_j2store` URL directly with their own parameters.

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 54 d ago (2026-09-15)

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CNA	4.0	5.3	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/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

Affected products

j2commerce.com J2Store extension for Joomla

Classification

Weakness

CWE-1241 Use of Predictable Algorithm in Random Number Generator

References

j2commerce.com /
product

Sources

CVE List CVE-2026-82191
NVD CVE-2026-82191

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary