Unauthenticated code execution via unrestricted file upload
Published Jun 29, 2026 · Updated Jun 29, 2026
Unrestricted file upload in Joomlack Page Builder CK before 3.6.0 allows remote attackers to execute PHP code without authentication. The front-end upload endpoint checks only a publicly exposed CSRF token, then accepts the destination folder, filename, and executable extension directly from the request. Any internet visitor can place PHP in a web-served writable directory and run it with the web server account, and observed attacks planted a persistent web shell.
Summary
What happened
Unrestricted file upload in Joomlack Page Builder CK before 3.6.0 allows remote attackers to execute PHP code without authentication. The front-end upload endpoint checks only a publicly exposed CSRF token, then accepts the destination folder, filename, and executable extension directly from the request. Any internet visitor can place PHP in a web-served writable directory and run it with the web server account, and observed attacks planted a persistent web shell.
The record
- CVE
- CVE-2026-56290
- Published
- Jun 29, 2026
- Updated
- Jun 29, 2026
- Vendor
- Joomlack
- Product
- Page Builder CK
- Classifications
- CWE-434, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 27, 2026Exploitation reportedPage Builder CK web-shell deployment
- Jun 29, 2026CVE publishedPublication date reported by the CVE source.
- Jun 29, 2026Record updatedLatest update available in the CVE record.
- Jul 7, 2026Exploitation reportedCISA Known Exploited Vulnerabilities Catalog listing
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.0-3.6.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Joomla Page Builder CK 3.5.10 Arbitrary File Uploadweaponized · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities Catalog listingknown exploited catalog
- Page Builder CK web-shell deploymentreported exploitation
Technologies
Your stack
See the directory against your own environment.
Your stack
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