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Fencer Vulns
critical 9.8

CVE-2026-56290 kev in the critical feed json

Joomla Extension - joomlack.fr - Unauthenticated file upload in Page Builder CK extension < 3.6.0

published 2026-06-29 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-40121

cvss
9.8
version 3.1, NVD
cisa kev
Exploited
added 2026-07-07
epss
30.9%
EPSS 30.9% chance of exploitation in 30 days, percentile 98%
public exploits
1
Exploit-DB, plus a Nuclei check

Summary

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.

Patch / fix

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.

  • joomlack page_builder_ck 3.6.0

Timeline

  1. Published
  2. Added to CISA KEV
  3. First public exploit (EDB-52626)
  4. CISA SSVC: exploitation active
  5. CISA patch deadline

Known exploited

Added
4 mo ago
Patch by
2026-07-10 (4 mo ago)
Ransomware
Not known
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.
Vendor, product
Joomlack, Page Builder
CISA name
Joomlack Page Builder Improper Access Control Vulnerability

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
yes
Technical impact
total
Assessed
4 mo ago

Exploit prediction

30.87% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • EDB-52626 Joomla Page Builder CK 3.5.10 - Arbitrary File Upload webapps, 2026-07-08
  • Nuclei template Page Builder CK <= 3.5.10 - Unauthenticated Arbitrary File Upload nuclei detection template
  • mysites.guru https://mysites.guru/blog/pagebuilderck-unauthenticated-file-upload-rce/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 10.0 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
CNA 4.0 10.0 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
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • joomlack.fr JoomlaCK.fr Page Builder CK extension for Joomla

Classification

Weakness
  • CWE-434 Unrestricted Upload of File with Dangerous Type

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.