---
id: "CVE-2026-56290"
kind: "vulnerability"
aliases: ["CVE-2026-56290"]
title: "joomlack page builder ck: Joomla Extension - joomlack.fr - Unauthenticated file upload in Page Builder CK extension < 3.6.0 - The Joomla\u2026"
severity: "critical"
cvss: 10.0
epss: null
exploited: true
status: "open"
category: "package"
products: [{"name": "Joomlack Page Builder", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "joomlack page builder ck", "fixed": ["3.6.0"], "affected": "< 3.6.0", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "joomla", "joomlack-page-builder", "package", "self-hosted"]
not_affected_if: ["joomla-without-joomlack"]
published_at: "2026-06-29T15:16:42+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-23T23:44:51+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-56290", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56290", "first_seen_at": "2026-10-23T23:44:51+00:00"}]
---

# joomlack page builder ck: Joomla Extension - joomlack.fr - Unauthenticated file upload in Page Builder CK extension < 3.6.0 - The Joomla…

Joomlack Page Builder, a Joomla extension, has an improper access control flaw that lets an unauthenticated visitor upload arbitrary files. Uploading a crafted file can lead to remote code execution on the web server, and CISA lists it as actively exploited.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Joomlack Page Builder affected ? fixed ?
- vendor:joomlack page builder ck affected < 3.6.0 fixed 3.6.0

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-56290
- 2026-10-23T23:44:51+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-56290

## From the sources

Joomlack Page Builder contains an improper access control vulnerability that could allow for remote code execution via unauthenticated arbitrary file upload.

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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_