Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2026-56290

JoomlaCK.fr Page Builder CK extension for Joomla Arbitrary File Access

Joomlack.fr Page Builder CK extension for Joomla · 1.0-3.6.0

Watch CVE-2026-56290 Browse KEV feed
Severity
CVSS 10.0 · Critical
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
30.9%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-56290 is an unauthenticated vulnerability affecting JoomlaCK.fr Page Builder CK extension for Joomla. Joomla Extension - joomlack.fr - Unauthenticated file upload in Page Builder CK extension < 3.6.0 - The...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

JoomlaCK.fr Page Builder CK extension for Joomla 1.0-3.6.0.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

JoomlaCK.fr Page Builder CK extension for Joomla Arbitrary File Access

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.

joomlack.fr Affected
JoomlaCK.fr Page Builder CK extension for Joomla
1.0-3.6.0
Published
29 Jun 2026
Exploitation Reported
07 Jul 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

joomla cisa nuclei_scanner

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 07 Jul 2026

A trusted third party reported exploitation.

Proof of concept available

GitHub

Recorded 03 Jul 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

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Source Added
CISA First 2026-07-07 17:00 UTC
CVE 2026-07-07 18:20 UTC
All CISA Advisories 2026-07-07 19:20 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-56290.yaml 22 Jul 2026

Risk and context

Severity, weaknesses, and research context

CVSS v4.0

10.0 Critical

Potential damage if exploited. Separate from whether attackers are using it.

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

EPSS

30.9%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Unrestricted Upload of File with Dangerous Type CWE-434

Recent mention · All CISA Advisories

CISA Adds Three Known Exploited Vulnerabilities to Catalog

CISA has added three new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog, based on evidence of active exploitation. CVE-2026-48908 JoomShaper SP Page Builder Unrestricted Upload of File with Dangerous Type Vulnerability CVE-2026-55255 Langflow...

Read full advisory

All CVSS Scores

CVSS v4.0 10.0 Critical

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

CVSS v3.1 9.8 Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

katranSefa/CVE-2026-56290

github · Created 2026-09-05 10:35:27 UTC · 0 stars · AI assessment 90%

Page Builder CK <= 3.5.10 - Unauthenticated Arbitrary File Upload

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. 04:30 UTC

    Public PoC available

    Public proof-of-concept code published

  2. 04:30 UTC

    Nuclei template available

    Scanner coverage available

  3. 19:20 UTC

    KEV confirmed by All CISA Advisories

    Exploitation attested by an external source

  4. 18:20 UTC

    KEV confirmed by CVE

    Exploitation attested by an external source

  5. 17:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  6. 14:31 UTC

    CVE published

    Vulnerability disclosed publicly

  7. 11:57 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-56290

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2026-56290",
  "confidence": "Confirmed",
  "cvss_score": 10.0,
  "cvss_estimated": false,
  "epss_score": 0.30866,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}