Joomlack Page Builder Improper Access Control Vulnerability
joomlack.fr — JoomlaCK.fr Page Builder CK extension for Joomla
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
2.9%
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
- Jul 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
Affected packages
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?
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?
2.9% - meaning FIRST.org's EPSS model estimates a 2.9% probability this vulnerability will be exploited in the wild within 30 days (85% 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.
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