Concretecms: >> Concrete Cms >> 9.5.1 Security Vulnerabilities
Concrete CMS Area API's block-create endpoint in versions 9.2.0 to 9.5.2 did not invoke the block type controller's validate() method on submitted data, which, for file-referencing blocks such as hero_image and gallery, is where the referenced file is authorized against the user's file-manager visibility. As a result, an authenticated user holding the block-add scope could store, and cause the page to render, a reference to a file that the file-manager authorization policy would otherwise reject, disclosing that file's URL and preview to the editor and to visitors of the affected page. Under public file storage, the URL and thumbnail are exposed directly; under private storage, the disclosure is limited by the permission-checked download URL. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.1 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N. Thanks riodrwn for reporting.
CVSS Score
5.1
EPSS Score
0.002
Published
2026-09-11
Concrete CMS versions 9.5.0 through 9.5.2 are vulnerable to Open Redirect via the rcURL parameter. An attacker can craft a single link on the site's own domain that sends a user to an arbitrary external site immediately after authentication, facilitating phishing and credential theft. The same handling is present in the registration flow, giving a second entry point on sites with registration enabled. Concrete CMS versions prior to 9.5.0 do not include the rcURL parameter or this allowlist and are not affected. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.3 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Michal M. for reporting.
CVSS Score
5.3
EPSS Score
0.003
Published
2026-09-11
Concrete CMS before 9.5.3 is vulnerable to Cross-Site Request Forgery in the Move Multiple Groups feature. The dashboard/users/groups/bulkupdate/confirm() endpoint moved the selected group tree nodes without validating an action token, so a state-changing group move could be processed for an authenticated user who did not initiate it. Because relocating a group under a new parent causes that group's members to inherit the parent's permissions, a forged move can change effective authorization. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.7 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks riodrwn for reporting.
CVSS Score
5.7
EPSS Score
0.002
Published
2026-09-11
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