CVE-2026-56290
Published: 29 June 2026
Summary
CVE-2026-56290 is a critical-severity Improper Access Control (CWE-284) vulnerability in Joomlack Page Builder Ck. Its CVSS base score is 10.0 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 24.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-40121
Vulnerability details
The Joomla extension Page Builder CK is vulnerable to an unauthenticated arbitrary file upload that allows uploading executable files and leads to full RCE.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Unauthenticated arbitrary file upload in public-facing Joomla web app directly enables RCE via T1190.
CVEs Like This One
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
This control enforces ownership-based restrictions on portable storage device use, directly implementing access control over media insertion into organizational systems.
Hardware write-protect enforces access control on critical resources (e.g., firmware) independent of software state.
The access control policy and procedures directly mandate and enforce proper access control mechanisms across the organization.
Device lock enforces restricted access until re-authentication, directly reducing unauthorized use of active sessions.
Supervision and review of access control activities directly detects and remediates improper access configurations or usages.
Explicitly identifying and documenting actions permitted without identification or authentication enforces proper access control boundaries by defining justified exceptions.
By automatically labeling outputs with security attributes, the control supports attribute-based enforcement and reduces exploitability of improper access control weaknesses.
Associating and retaining security attributes with data directly supports enforcement of access control decisions across storage, processing, and transmission.
Hardening callouts derived
Configuration rules from DISA STIG baselines that reduce the attack surface for weaknesses of the type cited by this CVE. Derived transitively via CVE→CWE→STIG over `controls_xwalks` (authoritative rows only).
Oracle Linux 8 (2 rules)
- V-248597 There must be no "shosts.equiv" files on the OL 8 operating system. via CWE-284
- V-248598 There must be no ".shosts" files on the OL 8 operating system. via CWE-284
Oracle Linux 9 (2 rules)
- V-271758 OL 9 file systems must not contain .shosts files. via CWE-284
- V-271757 OL 9 file systems must not contain shosts.equiv files. via CWE-284
RHEL 7 (2 rules)
- V-204606 The Red Hat Enterprise Linux operating system must not contain .shosts files. via CWE-284
- V-204607 The Red Hat Enterprise Linux operating system must not contain shosts.equiv files. via CWE-284
RHEL 8 (2 rules)
- V-230284 There must be no .shosts files on the RHEL 8 operating system. via CWE-284
- V-230283 There must be no shosts.equiv files on the RHEL 8 operating system. via CWE-284