# CVE-2026-56290: Joomlack Page Builder Improper Access Control

> Unauthenticated attackers can upload executable files to the Page Builder CK extension, leading to remote code execution.

- **Severity:** Critical 10.0 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:A/AU:Y/U:Red`)
- **Exploited in the wild:** Yes, since 7 Jul 2026 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Jun 2026
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-gxrr-wfg5-xqqf

## What is CVE-2026-56290?

CVE-2026-56290 is a critical vulnerability in JoomlaCK.fr Page Builder CK extension for Joomla, published on 29 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Joomla Extension - joomlack.fr - Unauthenticated file upload in Page Builder CK extension < 3.6.0 - The Joomla extension Page Builder CK is vulnerable to an unauthenticated arbitrary file upload that allows uploading executable files and leads to full RCE.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2026-56290?

It affects 1 product.


Products: Joomlack Page Builder Ck.

## How do I fix CVE-2026-56290?

No fix has been published for CVE-2026-56290 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 10 Jul 2026.

## Is CVE-2026-56290 being exploited?

Yes. Attackers have exploited CVE-2026-56290 in the wild since at least 7 Jul 2026.

Public exploit code:

- CVE-2026-56290 - Mass Exploit for Joomla Com_pagebuilderck component (Unrestricted File Upload → RCE). Multi-threaded, automatic CSRF bypass, PHP shell uploader. (github_poc): https://github.com/Jenderal92/CVE-2026-56290
- 📤 Mass exploitation framework for CVE-2026-56290 — Page Builder CK Joomla unauthenticated file upload to RCE (github_poc): https://github.com/shinthink/pbck-exploit
- Page Builder CK for Joomla - Unauthenticated SSRF / Remote File Write leading to PHP execution Exploiter (github_poc): https://github.com/sagsooz/PageBuilderCK-CVE-2026-56290-Exploit
- Joomla Page Builder CK  3.5.10 -  Arbitrary File Upload (exploitdb)
- The Joomla extension Page Builder CK is vulnerable to an unauthenticated arbitrary file upload that allows uploading executable files and leads to full RCE. (github_poc): https://github.com/ChiefYoru/CVE-2026-56290_PoC
- https://github.com/katranSefa/CVE-2026-56290 (github_poc): https://github.com/katranSefa/CVE-2026-56290

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-56290 and fix it if it is affected.

What it is: CVE-2026-56290 is a critical vulnerability in JoomlaCK.fr Page Builder CK extension for Joomla, published on 29 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2026-56290 in the wild since at least 7 Jul 2026.

Affected product: JoomlaCK.fr Page Builder CK 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-2026-56290/ (Markdown: https://insights.sbomify.com/CVE-2026-56290/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-56290
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-56290
- OSV: https://osv.dev/vulnerability/CVE-2026-56290

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-56290/
Summaries are generated and may contain mistakes; the official description above is the record.