# CVE-2026-74252: 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

> An unauthenticated attacker can inject malicious scripts via guest checkout fields, potentially stealing user sessions or executing code in victim browsers.

- **Severity:** High 8.6 (`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`)
- **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:** 21 Aug 2026
- **Updated:** 21 Aug 2026
- **Also known as:** GHSA-42m7-jqh7-g85c

## What is CVE-2026-74252?

CVE-2026-74252 is a high-severity cross-site scripting vulnerability in j2commerce.com J2Store extension for Joomla, published on 21 Aug 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 - 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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-74252?


## How do I fix CVE-2026-74252?

No fix has been published for CVE-2026-74252 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-74252 being exploited?

There is no known exploitation of CVE-2026-74252 in the wild and no public exploit code.

Public exploit code:

- Stored XSS in J2Commerce Guest Checkout via Cookie Filter Bypass (github_poc): https://github.com/toanln-cov/CVE-2026-74252

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74252 and fix it if it is affected.

What it is: CVE-2026-74252 is a high-severity cross-site scripting vulnerability in j2commerce.com J2Store extension for Joomla, published on 21 Aug 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-2026-74252 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-2026-74252/ (Markdown: https://insights.sbomify.com/CVE-2026-74252/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74252
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74252
- OSV: https://osv.dev/vulnerability/CVE-2026-74252

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-74252/
Summaries are generated and may contain mistakes; the official description above is the record.