How severe is CVE-2026-56290?

No CVSS score has been assigned to CVE-2026-56290 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-56290?

Affected package information for CVE-2026-56290 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-56290?

The records we use list no fixed release for CVE-2026-56290. Check the upstream advisory for a patched version, and apply the exposure-reduction steps below in the meantime.

How do I detect CVE-2026-56290 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2026-56290 if there is no patch (or I can't update yet)?

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.

Is CVE-2026-56290 actively exploited in the wild?

Yes. There are 3 known exploit references for CVE-2026-56290, including 1 documented proof-of-concept exploit on Exploit-DB. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2026-56290?

CVE-2026-56290 has an EPSS (Exploit Prediction Scoring System) score of 30.9%, placing it in the 98th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

Is CVE-2026-56290 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2026-56290 (Joomlack Page Builder Improper Access Control Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-07-07. CISA required all US federal civilian agencies to remediate this vulnerability by 2026-07-10. The required action was: 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. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2026-56290?

CVE-2026-56290 is classified as Unrestricted File Upload (CWE-434). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Is there exploit tooling available for CVE-2026-56290?

A Nuclei detection template exists for CVE-2026-56290, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2026-56290 published, and has it been updated?

CVE-2026-56290 was published on June 29, 2026 and was last updated on October 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV · ACTIVELY EXPLOITED

CVE-2026-56290

CVE-2026-56290 is a Unrestricted File Upload vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2026-07-07) — treat it as actively exploited and patch now. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

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…

Published

Jun 29, 2026

Updated

Oct 8, 2026

Affected

1 product

Patched

See advisory

Exploits

3 known

Exploitation data as of Nov 13, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

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

via FIRST.org ↗

30.9%probability of exploitation in next 30 days

Moderate Risk0.00%

Lower risk than most CVEs98th percentile — riskier than 98% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

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

1 product · 1 configurations

Application

page builder ckjoomlack

< 3.6.0

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-52626webappsmultiple

Joomla Page Builder CK 3.5.10 - Arbitrary File Upload

by M@rAz Ali · Jul 8, 2026

Exploit-DB Source

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
The records we use list no fixed release for CVE-2026-56290. Check the upstream advisory for a patched version, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
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.

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

O3 Security · Impact-Aware SCA

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