CVE-2026-56290: JoomlaCK.fr Page Builder CK extension for Joomla · Unrestricted File Upload
Affects JoomlaCK.fr Page Builder CK extension for JoomlaSource CVE Database V5
Exploited in the wild · KEV due 10 Jul 2026 · public exploit available (Exploit-DB) · 30% EPSS : apply the vendor's fix or mitigations to JoomlaCK.fr Page Builder CK extension for Joomla now.
Data as of 12 Nov 2026, 23:24 UTC
- KEV deadline
- US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
- EPSS
- 30.8% chance of exploitation in 30 days – higher than 98% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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:RedExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 29 Jun 2026
Detectable: evidence found.
nuclei template: Page Builder CK <= 3.5.10 - Unauthenticated Arbitrary File Upload
Weaponized: evidence found.
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 8 days after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by Joomla! Project
, 9 days before disclosure
CVE published
on cve.org
, t = 0
In Threat Radar
record ingested
, 20 minutes after disclosure
Added to CISA KEV (opens in a new tab)
exploitation confirmed
, 8 days after disclosure
First Exploit-DB entry (opens in a new tab)
Joomla Page Builder CK 3.5.10 - Arbitrary File Upload
, 9 days after disclosure
KEV remediation due
US federal deadline
, 11 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
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.fr/en/joomla-extensions/page-builder-ck (opens in a new tab)
- cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (opens in a new tab)
- cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-56290 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| joomlack.frJoomlaCK.fr Page Builder CK extension for Joomla | Affected
| Fixed in– |
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.
References
- joomlack.fr (opens in a new tab)
- mysites.guru/blog/pagebuilderck-unauthenticated-file-upload-rce/ (opens in a new tab)
- forum.joomlack.fr/index.php/page-builder-ck/21627-nouvelle-version-de-pbck-et-joomla-3 (opens in a new tab)
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56290 (opens in a new tab)