Arbitrary file upload in Joomlack Page Builder Ck

CVE-2026-56290

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.

Vulnerability class: Unrestricted File Upload

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS 0.309, 98.3th percentile (scored ); unchanged over 30 days. About EPSS.

Affected products

Weakness classification (CWE)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: .

Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Browse the full CISA KEV catalog with PoC counts, Metasploit modules and EPSS.

Public exploits and proof-of-concept code

6 public repositories with exploit or proof-of-concept code for this CVE:

  • Jenderal92/CVE-2026-56290 (5 stars, last pushed 2026-07-08): CVE-2026-56290 - Mass Exploit for Joomla Com_pagebuilderck component (Unrestricted File Upload → RCE). Multi-threaded, automatic CSRF bypass, PHP shell uploader.
  • shinthink/pbck-exploit (3 stars, last pushed 2026-07-04): 📤 Mass exploitation framework for CVE-2026-56290 — Page Builder CK Joomla unauthenticated file upload to RCE
  • sagsooz/PageBuilderCK-CVE-2026-56290-Exploit (2 stars, last pushed 2026-07-04): Page Builder CK for Joomla - Unauthenticated SSRF / Remote File Write leading to PHP execution Exploiter
  • Mushr00w/CVE-2026-56290 (last pushed 2026-11-12): Unauthenticated Remote Code Execution in Joomla Page Builder CK <= 3.5.10.
  • katranSefa/CVE-2026-56290 (last pushed 2026-09-05)
  • ChiefYoru/CVE-2026-56290_PoC (last pushed 2026-07-19): The Joomla extension Page Builder CK is vulnerable to an unauthenticated arbitrary file upload that allows uploading executable files and leads to full RCE.

References

This CVE has public exploit evidence. See the latest CVEs with public exploits.