CVE-2026-56290

Published Jun 29, 2026

Last updated 10 hours ago

Overview

AI description

Automated description summarized from trusted sources.

CVE-2026-56290 describes an unauthenticated arbitrary file upload vulnerability found within the Joomla extension Page Builder CK. This flaw allows an attacker to upload executable files to the affected system. The successful exploitation of this vulnerability can lead to full remote code execution (RCE) on the compromised system, as no authentication is required for an attacker to perform the file upload. This vulnerability is categorized under CWE-284, which pertains to improper access control. It has also been added to CISA's Known Exploited Vulnerabilities Catalog.

Description: The Joomla extension Page Builder CK is vulnerable to an unauthenticated arbitrary file upload that allows uploading executable files and leads to full RCE.
Source: security@joomla.org
NVD status: Undergoing Analysis
Products: page_builder_ck

Risk scores

CVSS 4.0

Type: Secondary
Base score: 10
Impact score: -
Exploitability score: -
Vector string: 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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:X/V:X/RE:X/U:Red
Severity: CRITICAL

CVSS 3.1

Type: Primary
Base score: 9.8
Impact score: 5.9
Exploitability score: 3.9
Vector string: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: CRITICAL

Known exploits

Data from CISA

Vulnerability name: Joomlack Page Builder Improper Access Control Vulnerability
Exploit added on: Jul 7, 2026
Exploit action due: Jul 10, 2026
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.

Weaknesses

security@joomla.org: CWE-434
nvd@nist.gov: CWE-434

Hype score is a measure of social media activity compared against trending CVEs from the past 12 months. Max score 100.

Hype score: 10

Configurations

[
  {
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:joomlack:page_builder_ck:*:*:*:*:*:joomla\\!:*:*",
            "matchCriteriaId": "57D7FD08-F3BF-47D8-9EFF-E8CF1D474D38",
            "versionEndIncluding": "3.6.0",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ]
  }
]

References

Sources include official advisories and independent security research.