CVE-2026-56290 — Page Builder Ck
CRITICALCVE-2026-56290 is a critical-severity (CVSS 9.8) Unrestricted File Upload vulnerability in joomlack page builder ck. It is in CISA's Known Exploited Vulnerabilities catalog (added 2026-07-07) — treat it as actively exploited and patch now. A fix is available — see the affected versions and patch details below.
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…
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2026-07-07. Federal agencies were required to remediate by 2026-07-10.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2026-56290.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-56290 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 380,066 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Counts from FIRST.org, log-scaled.
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.
Affected Products
page builder ckjoomlackResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Joomla Page Builder CK 3.5.10 - Arbitrary File Upload
by M@rAz Ali · Jul 8, 2026
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every joomlack page builder ck deployment and check each version against the affected-products list above.
Fix
Apply the joomlack page builder ck security patch or hotfix for CVE-2026-56290 on the affected version, following the vendor advisory for your exact build.
Workarounds
Treat uploaded files as untrusted until proven otherwise: validate the actual content type rather than the supplied extension, store uploads outside the web root on a volume mounted without execute permission, and rename them to server-generated identifiers so an attacker cannot choose the path a request will later resolve. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
How to detect CVE-2026-56290
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2026-56290 -u https://target- Template
- Page Builder CK <= 3.5.10 - Unauthenticated Arbitrary File Upload
- Severity
- critical
Template by ProjectDiscovery nuclei-templates (panchiko-p, 0x_Akoko), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2026-56290 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.