# CVE-2026-82191: Open redirect in J2Store extension for Joomla

> Attackers can craft links that redirect victims to a checkout controller with injected parameters, potentially bypassing intended flow restrictions.

- **Severity:** Medium 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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 15 Sep 2026
- **Updated:** 15 Sep 2026
- **Also known as:** GHSA-hv62-7458-mg3v

## What is CVE-2026-82191?

CVE-2026-82191 is a medium-severity vulnerability in j2commerce.com J2Store extension for Joomla, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

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.

Weakness: CWE-1241 (Use of Predictable Algorithm in Random Number Generator)

## Which versions are affected by CVE-2026-82191?


## How do I fix CVE-2026-82191?

No fix has been published for CVE-2026-82191 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-82191 being exploited?

There is no known exploitation of CVE-2026-82191 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-82191 and fix it if it is affected.

What it is: CVE-2026-82191 is a medium-severity vulnerability in j2commerce.com J2Store extension for Joomla, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-82191 in the wild and no public exploit code.

Affected product: j2commerce.com J2Store extension for Joomla. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-82191/ (Markdown: https://insights.sbomify.com/CVE-2026-82191/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-82191
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-82191
- OSV: https://osv.dev/vulnerability/CVE-2026-82191

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-82191/
Summaries are generated and may contain mistakes; the official description above is the record.