Concrete CMS is vulnerable to IDOR in AddMessage/UpdateMessage

TRUNG BÌNH 4.3CVE-2026-7886 · GHSA-p8p9-5953-h9jw · Công bố 21/05/2026 · cập nhật 23/07/2026

Tóm tắt nhanh

CVE-2026-7886 là lỗ hổng mức TRUNG BÌNH (CVSS 4.3) ảnh hưởng concrete5/concrete5, concrete cms (concretecms).
Xác suất bị khai thác trong 30 ngày tới (EPSS): 0.29%, cao hơn 21.4% các lỗ hổng khác.
Cách xử lý: cập nhật lên 9.5.1 hoặc mới hơn.

Gói / sản phẩm	Phiên bản bị ảnh hưởng	Phiên bản đã vá
concrete5/concrete5 Packagist	`< 9.5.1`	`9.5.1`
concrete cms concretecms	`< 9.5.1`	`9.5.1`

Mô tả

Concrete CMS 9.5.0 and below is vulnerable to IDOR in AddMessage/UpdateMessage via attachments[] parameter which can lead to file permission bypass. The AddMessage and UpdateMessage conversation controllers accept user-supplied file attachment IDs and load files directly via $em->find(File::class, $attachmentID) without checking per-file permissions (canViewFile()). A user who can post in any conversation can reference any file in the CMS file manager by its sequential ID, effectively bypassing the file permission system. If a site truly has private files, the owner should set up a private storage location https://documentation.concretecms.org/user-guide/editors-reference/dashboard/system-and-maintenance/files/file-storage-locations outside of the webroot so that permissions can be checked on view as well. That way, even if an authorized user attaches a file, or otherwise links to it, unauthorized users won't be able to view the file.

Mô tả của NVD

Concrete CMS 9.5.0 and below is vulnerable to IDOR in AddMessage/UpdateMessage via attachments[] parameter which can lead to file permission bypass. The `AddMessage` and `UpdateMessage` conversation controllers accept user-supplied file attachment IDs and load files directly via `$em->find(File::class, $attachmentID)` without checking per-file permissions (`canViewFile()`). A user who can post in any conversation can reference any file in the CMS file manager by its sequential ID, effectively bypassing the file permission system. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.3 with a vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Tristan Mandani for reporting. if a site truly has private files, the owner should set up a private storage location https://documentation.concretecms.org/user-guide/editors-reference/dashboard/system-and-maintenance/files/file-storage-locations outside of the webroot so that permissions can be checked on view as well. That way, even if a authorized user attaches a file, or otherwise links to it, unauthorized users won't be able to view the file.