CVE-2026-56290
Joomlack Page Builder Improper Access Control Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 10 July 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 4.0
- 10.0 CRITICALCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 30.87% probability · 98th percentile
- Public exploits
- 1 in Exploit-DB · first 8 July 2026
- CISA KEV
- Listed 7 July 2026 · due 10 July 2026
- Weakness
- CWE-434
- Affected
- joomlack/page builder ck
- Source
- security@joomla.org
EPSS 30.9% since 27 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
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. https://www.joomlack.fr/en/joomla-extensions/page-builder-ck ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-56290
Public exploits (1)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- https://www.joomlack.fr/Product
- https://forum.joomlack.fr/index.php/page-builder-ck/21627-nouvelle-version-de-pbck-et-joomla-3Issue 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-2026-56290US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.