Concretecms: >> Concrete Cms Security Vulnerabilities
Concrete CMS 9.5.2 and below is vulnerable to stored DOM-based Cross-site Scripting (XSS) via the Gallery block's per-image Caption field because the bundled Magnific Popup lightbox script (concrete/js/features/imagery/frontend.js) re-parses the attribute-decoded caption as HTML through jQuery's .append() in titleSrc instead of inserting it as text. A user with permission to edit a page containing a Gallery block can store a caption that executes in the browser of any visitor who opens that image's lightbox. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 8.5 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Yonatan Drori (Tenzai) for reporting.
CVSS Score
8.5
EPSS Score
0.002
Published
2026-09-15
In Concrete CMS before 9.5.3, the Document Library block stored the file-set identifiers submitted through fsID[] without validating them as integers, and when the block was configured with setMode set to any it concatenated each stored identifier directly into the file-set filter query instead of casting it or binding it as a parameter. An authenticated user permitted to add or edit a Document Library block could therefore persist SQL syntax in the block configuration (btDocumentLibrary.setIds), and that stored expression was executed every time the published page containing the block was rendered, producing stored, time-based blind SQL injection. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 8.5 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Habib Allah for reporting.
CVSS Score
8.5
EPSS Score
0.005
Published
2026-09-15
Concrete CMS before 9.5.3 does not apply HTML entity encoding to user-defined Form block question labels when rendering them as column headers in the Dashboard Form Submissions report (concrete/single_pages/dashboard/reports/forms/legacy.php). a rogue editor could store markup or script in a label that then executes in the browser of any administrator who opens the submissions report for the affected form, producing stored cross-site scripting in the Dashboard. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 8.4 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.
CVSS Score
8.4
EPSS Score
0.002
Published
2026-09-15
In Concrete CMS below CMS 9.5.3, the save_control action in the Express entities forms dashboard controller did not validate the anti-CSRF token. By causing an authenticated administrator to submit a forged cross-site request, a remote attacker without credentials could write attacker-controlled headline and body values to an existing Express form Text control. Those values were emitted without output encoding by the Express form Text element, so the injected markup executed as persistent JavaScript for any administrator who later opened the affected entry, resulting in stored cross-site scripting. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.7 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.
CVSS Score
7.7
EPSS Score
0.002
Published
2026-09-15
Concrete CMS 9 (9.0.0 through 9.5.2) does not perform an authorization check on the user selector autocomplete endpoint (/ccm/system/user/autocomplete), which backs the "Preview as User" panel and other user-selector components. The endpoint validates only a CSRF-style access token that is bound to the selector's display options rather than to the caller's identity or permissions, and that token is issued to anonymous visitors because the selector renders without an authorization check. Because an empty query resolves to a match-all filter, an unauthenticated attacker can submit an empty search and paginate the results to enumerate every backend account, disclosing the internal user ID, username, and email address of all administrative users, including the super-administrator (user ID 1). No password hashes or session material are disclosed The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 8.7 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks thirtythree and YesWeHack for reporting.
CVSS Score
8.7
EPSS Score
0.003
Published
2026-09-15
Concrete CMS before 9.5.3 applied only trim() to the YouTube block's stored width and height values and printed them into iframe HTML attributes without escaping or integer casting, resulting in stored cross-site scripting. A user with edit_block permission could inject an event handler that executed script for visitors rendering the page, acting with administrative privileges where the victim was an administrator. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks sh4d0byss for reporting.
CVSS Score
7.3
EPSS Score
0.003
Published
2026-09-14
Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard "Waiting For Me" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting.
CVSS Score
7.3
EPSS Score
0.002
Published
2026-09-14
Concrete CMS 9.0.0 through 9.5.3 is vulnerable to stored XSS via the custom page alias name (customAliasName) because the Edit Alias dialog applied only trim() to the submitted value and performed no input neutralization. An authenticated user holding canWrite (editor) permission on a page could store a malicious alias name that was later rendered unescaped in the administrative Sitemap panel, where it executed automatically in any administrator or editor session that opened the panel, allowing an editor to escalate to administrator through the victim's active session. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N. Thanks Nguyen Manh Thuan for reporting.
CVSS Score
7.3
EPSS Score
0.001
Published
2026-09-14
In Concrete CMS 9.2.0 through 9.5.2, the REST API page update endpoint (PUT /ccm/api/1.0/pages/{cID}) did not enforce page-property, page-template, or page-type authorization. A user granted only content-editing rights on a page could therefore alter its properties, template, and type through the API, and could set the header_extra_content attribute, which is rendered unescaped into the head element of every page, to persist JavaScript that executed in the browser of every visitor, including higher-privileged reviewers who approve the page version. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.2 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.
CVSS Score
7.2
EPSS Score
0.004
Published
2026-09-14
Concrete CMS 9 through 9.5.2 did not validate a CSRF token in the orphaned block removal panel action (removeOrphanedBlocks). A remote attacker could craft a request that, when loaded by an authenticated user holding edit permission on the target page, deleted every block on that page's current version; blocks not aliased to another page or scrapbook entry were also removed from the global Blocks table and their block-type data table, permanently destroying the content. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.1 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.
CVSS Score
7.1
EPSS Score
0.002
Published
2026-09-14