CVEs / CVE-2026-56290
CVE-2026-56290: Joomlack Page Builder Improper Access Control Vulnerability
- Known exploited in the CISA KEV catalog since 7 Jul 2026
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 30.8% chance of exploitation in the next 30 days, higher than 98% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Joomlack Page Builder contains an improper access control vulnerability that could allow for remote code execution via unauthenticated arbitrary file upload.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| joomlack.fr JoomlaCK.fr Page Builder CK extension for Joomla | 1.0-3.6.0 | — |
Exploitation
| In CISA KEV since | 7 Jul 2026 |
|---|---|
| Due date for US federal agencies | 10 Jul 2026 |
| Used in ransomware campaigns | Unknown |
| 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. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-434 |
References
- CVE-2026-56290 on NVD
- CVE-2026-56290 in the CISA KEV catalog
- https://www.joomlack.fr/en/joomla-extensions/page-builder-ck (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.joomlack.fr/ Product
- https://forum.joomlack.fr/index.php/page-builder-ck/21627-nouvelle-version-de-pbck-et-joomla-3 Issue Tracking, Patch
- https://mysites.guru/blog/pagebuilderck-unauthenticated-file-upload-rce/ Exploit, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56290 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.