# CVE-2026-56290 — joomlack.fr Page Builder CK extension for Joomla **CISA KEV** > As of 2026-10-08, CVE-2026-56290 is a CRITICAL-severity vulnerability in joomlack.fr Page Builder CK extension for Joomla, CVSS v3.1 9.8, EPSS 30.8% (98.2th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-07-07), with a US federal remediation deadline of 2026-07-10. Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2026-56290, most recently “Zero-Day Exploitation of Joomla iCagenda and Balbooa Forms Extensions via Unauthenticated Arbitrary File Upload (CVE-2026-48939, CVE-2026-56291)”. **Last updated:** 2026-10-08 ## What is CVE-2026-56290? 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. The record classifies CVE-2026-56290 under weakness class [CWE-434](https://intel.threadlinqs.com/cwe/CWE-434). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 121 days ago. ## Severity and exploitation probability - **CVSS v3.1 base score:** 9.8 — CRITICAL (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`) - **CVSS v4.0 base score:** 10 (`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 (FIRST):** 30.8% probability of exploitation in the next 30 days, higher than 98.2% of all scored CVEs - **CISA KEV:** Listed since 2026-07-07, federal remediation deadline 2026-07-10 - **Threadlinqs priority:** 9/10 — CISA KEV-listed, which Threadlinqs floors at 9 - **Published:** 2026-06-29, last modified 2026-10-08 ## Is CVE-2026-56290 being exploited? CISA added CVE-2026-56290 to the Known Exploited Vulnerabilities catalog on 2026-07-07, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-07-10 under BOD 22-01. Weaponised exploit code for CVE-2026-56290 is publicly available. 5 public proof-of-concept repositories are tracked for this identifier. A ProjectDiscovery Nuclei detection template exists (`http/cves/2026/CVE-2026-56290.yaml`). It currently carries a trending score of 54 in the Threadlinqs vulnerability feed. - [Jenderal92/CVE-2026-56290](https://github.com/Jenderal92/CVE-2026-56290) (github) - [shinthink/pbck-exploit](https://github.com/shinthink/pbck-exploit) (github) - [sagsooz/PageBuilderCK-CVE-2026-56290-Exploit](https://github.com/sagsooz/PageBuilderCK-CVE-2026-56290-Exploit) (github) - [ChiefYoru/CVE-2026-56290_PoC](https://github.com/ChiefYoru/CVE-2026-56290_PoC) (github) - [katranSefa/CVE-2026-56290](https://github.com/katranSefa/CVE-2026-56290) (github) ## Affected products and versions - **joomlack.fr**: Page Builder CK extension for Joomla ## How to fix CVE-2026-56290 The record marks a vendor fix as available for CVE-2026-56290. Patch reference: [https://forum.joomlack.fr/index.php/page-builder-ck/21627-nouvelle-version-de-pbck-et-joomla-3](https://forum.joomlack.fr/index.php/page-builder-ck/21627-nouvelle-version-de-pbck-et-joomla-3). Because CVE-2026-56290 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-07-10. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory. ## Threat activity tracking CVE-2026-56290 2 tracked threats in the Threadlinqs corpus reference CVE-2026-56290, either in the campaign’s CVE list or as an indicator on the campaign record. - [Zero-Day Exploitation of Joomla iCagenda and Balbooa Forms Extensions via Unauthenticated Arbitrary File Upload (CVE-2026-48939, CVE-2026-56291)](https://intel.threadlinqs.com/threat/TL-2026-1254) — CRITICAL · 2026-07-13 - [CISA Warns of Actively Exploited RCE Flaws in Joomla Extensions — iCagenda (CVE-2026-48939) and Balbooa Forms (CVE-2026-56291) Arbitrary File Upload](https://intel.threadlinqs.com/threat/TL-2026-1267) — CRITICAL · 2026-07-13 ## Sources Enriched from CVE.org, NVD, FIRST EPSS, CISA KEV, GitHub Security Advisories, public proof-of-concept repositories, ProjectDiscovery Nuclei. Last verified by Threadlinqs on 2026-10-11. This product uses the NVD API but is not endorsed or certified by the NVD. **Issue tracking and product pages** - [joomlack.fr — product](https://www.joomlack.fr/) Canonical: https://intel.threadlinqs.com/cve/CVE-2026-56290 Full detection coverage and IOCs for threats exploiting CVE-2026-56290 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp