CVE-2026-8134

Published: Mag 21, 2026 Last Modified: Mag 21, 2026
ExploitDB:
Other exploit source:
Google Dorks:
CRITICAL 9,4
Source: ff5b8ace-8b95-4078-9743-eac1ca5451de
Attack Vector: network
Attack Complexity: low
Privileges Required: high
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A

Description

AI Translation Available

Concrete CMS 9.5.0 and below fails to sanitize path traversal sequences in the ptComposerFormLayoutSetControlCustomTemplate field when saving page type composer form layouts. An authenticated rogue administrator with composer form editing rights can exploit this to include arbitrary readable files on the server. Combined with the file uploader's extension-only validation (which permits PHP code in files saved with image extensions like .png), this can result in authenticated remote code execution. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 9.4 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H   Thanks Yonatan Drori (Tenzai) for reporting.

23

Relative Path Traversal

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Confidentiality Availability
Potential Impacts:
Execute Unauthorized Code Or Commands Modify Files Or Directories Read Files Or Directories Dos: Crash, Exit, Or Restart
Applicable Platforms
Technologies: Not Technology-Specific, Web Based, AI/ML
View CWE Details
98

Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion')

Draft
Abstraction: Variant Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Confidentiality Availability
Potential Impacts:
Execute Unauthorized Code Or Commands
Applicable Platforms
Languages: PHP
Technologies: Web Based, Web Server
Likelihood of Exploit: High
View CWE Details
434

Unrestricted Upload of File with Dangerous Type

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Confidentiality Availability
Potential Impacts:
Execute Unauthorized Code Or Commands
Applicable Platforms
Languages: ASP.NET, PHP, Not Language-Specific
Technologies: Web Server, AI/ML
Likelihood of Exploit: Medium
View CWE Details
https://documentation.concretecms.org/9-x/developers/introd…
https://documentation.concretecms.org/9-x/developers/introduction/version-histo…