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.
Advisories
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Fixes
Solution
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Workaround
No workaround given by the vendor.
References
History
Thu, 21 May 2026 21:45:00 +0000
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Concretecms
Concretecms concrete Cms |
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Concretecms
Concretecms concrete Cms |
Thu, 21 May 2026 20:30:00 +0000
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| Description | 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. | |
| Title | Concrete CMS 9.5.0 and below is vulnerable to Authenticated RCE via Composer customTemplate Path Traversal leading to PHP File Inclusion | |
| Weaknesses | CWE-23 CWE-434 CWE-98 |
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| References |
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| Metrics |
cvssV4_0
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Projects
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Status: PUBLISHED
Assigner: ConcreteCMS
Published:
Updated: 2026-05-21T20:13:31.343Z
Reserved: 2026-05-07T17:49:33.331Z
Link: CVE-2026-8134
No data.
Status : Received
Published: 2026-05-21T21:16:32.837
Modified: 2026-05-21T21:16:32.837
Link: CVE-2026-8134
No data.
OpenCVE Enrichment
Updated: 2026-05-21T21:30:19Z