Joomlack Page Builder Improper Access Control Vulnerability
joomlack.fr — JoomlaCK.fr Page Builder CK extension for Joomla
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.
10.0
30.4%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (Vulnerable System)
- High
- Integrity (Vulnerable System)
- High
- Availability (Vulnerable System)
- High
- Confidentiality (Subsequent System)
- High
- Integrity (Subsequent System)
- High
- Availability (Subsequent System)
- High
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
- Published
- Jun 29, 2026
- Modified
- Oct 8, 2026
- Added to KEV
- Jul 7, 2026
- Federal patch due
- Jul 10, 2026
CISA 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.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2026-56290, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit — cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2026-56290 were found at last check. Absence here is not proof no exploit exists — see the references below for vendor advisories and write-ups.
References
Frequently asked questions
What is 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.
How severe is CVE-2026-56290?
CVE-2026-56290 has a CVSS base score of 10.0 out of 10 (CVSS 4.0).
Is CVE-2026-56290 actively exploited in the wild?
Yes. CVE-2026-56290 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Jul 7, 2026, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2026-56290?
30.4% - meaning FIRST.org's EPSS model estimates a 30.4% probability this vulnerability will be exploited in the wild within 30 days (98% percentile among all scored CVEs).
Is there exploit tooling available for CVE-2026-56290?
Yes - a public Nuclei template referencing CVE-2026-56290 exist in public repositories we checked.
What type of vulnerability is CVE-2026-56290?
CVE-2026-56290 is classified under CWE-434 (CWE-434: Unrestricted Upload of File with Dangerous Type).
Cross-checked against
Impactr finds and proves whether CVE-2026-56290 — or flaws like it — are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.