CVE-2026-89145 Flextype CMS 0.9.9 through 1.0.0-alpha.3 Stored XSS via Plugin Directory

Flextype CMS versions 0.9.9 through 1.0.0-alpha.3 fail to HTML-escape plugin directory names in the dependency error page rendered by getValidPluginsDependencies. Attackers with write access to the plugins directory can create a plugin with HTML characters in its name to execute arbitrary scripts...

EUVD-2026-75896

Flextype CMS versions 0.9.9 through 1.0.0-alpha.3 fail to HTML-escape plugin directory names in the dependency error page rendered by getValidPluginsDependencies. Attackers with write access to the plugins directory can create a plugin with HTML characters in its name to execute arbitrary scripts...

EUVD-2026-75887

Concrete CMS below 9.5.3 stores user validation hashes for multiple purposes email/registration validation, password reset, and persistent login in a single table with a type column, but the redemption path resolves a hash by value alone and does not verify its type. As a result, a hash issued fo...

EUVD-2026-75885

Concrete CMS 9.5.2 and below is vulnerable to an authorization bypass IDOR because the frontend calendar lightbox endpoint /ccm/calendar/viewevent/bID/occurrenceid does not verify that the caller is permitted to view the calendar that owns the requested event occurrence. The controller loads the...

EUVD-2026-75888

Concrete CMS OAuth callback login path prior to version 9.5.3 did not check whether an account was active or email-validated before establishing a session. A deactivated or unvalidated user with an existing OAuth binding could complete authentication and receive a session that was fully...

CVE-2026-81905

Concrete CMS below 9.5.3 stores user validation hashes for multiple purposes email/registration validation, password reset, and persistent login in a single table with a type column, but the redemption path resolves a hash by value alone and does not verify its type. As a result, a hash issued fo...

CVE-2026-81906

Concrete CMS OAuth callback login path prior to version 9.5.3 did not check whether an account was active or email-validated before establishing a session. A deactivated or unvalidated user with an existing OAuth binding could complete authentication and receive a session that was fully...

CVE-2026-18121

Concrete CMS 9.5.2 and below is vulnerable to an authorization bypass IDOR because the frontend calendar lightbox endpoint /ccm/calendar/viewevent/bID/occurrenceid does not verify that the caller is permitted to view the calendar that owns the requested event occurrence. The controller loads the...

PT-2026-90054

Name of the Vulnerable Software and Affected Versions Concrete CMS versions prior to 9.5.3 Description An issue exists where the system fails to validate an anti-CSRF token a unique token used to prevent Cross-Site Request Forgery, where an attacker tricks a user into performing actions they did...

PT-2026-90149

Name of the Vulnerable Software and Affected Versions Concrete CMS versions prior to 9.5.3 Description Cross-Site Request Forgery CSRF exists in the Move Multiple Groups feature. The endpoint 'dashboard/users/groups/bulkupdate/confirm' allows moving selected group tree nodes without validating an...

PT-2026-90496

Name of the Vulnerable Software and Affected Versions Concrete CMS versions prior to 9.5.3 Description Cross-Site Request Forgery CSRF occurs in the Express Clear Entries function. The issue exists because the controller records a failed CSRF token check but does not enforce it, allowing...

CVE-2026-18121: Missing Authorization

Concrete CMS 9.5.2 and below is vulnerable to an authorization bypass IDOR because the frontend calendar lightbox endpoint /ccm/calendar/viewevent/bID/occurrenceid does not verify that the caller is permitted to view the calendar that owns the requested event occurrence. The controller loads the...

CVE-2026-81913: URL Redirection to Untrusted Site

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...

CVE-2026-81916: Missing Authorization

Concrete CMS before 9.5.3 evaluated the authorization check for an Express entry submission against the entity of the posted form rather than the entity identified by the dashboard route. As a result, a user permitted to add entries to one Express object could create entries in a different Expres...

PT-2026-90002

Concrete CMS 9 through 9.5.2 is vulnerable to Missing Authorization in the block alias route Process::alias in concrete/controllers/backend/block/process.php.It does not verify that the referenced block is genuinely orphaned on the target page, nor that the caller holds any permission over the...

PT-2026-90497

Name of the Vulnerable Software and Affected Versions Concrete CMS versions prior to 9.5.3 Description An authorization flaw exists during Express entry submissions where the system validates the authorization check against the entity of the posted form instead of the entity identified by the...

PT-2026-90150

Name of the Vulnerable Software and Affected Versions Concrete CMS versions 9.5.0 through 9.5.2 Description An open redirect exists where an attacker can craft a link on the site's own domain to send users to an arbitrary external site immediately after authentication or during the registration...

CVE-2026-81911: Improper Neutralization of Input During Web Page Generation

Concrete CMS versions 9.0.0 to 9.5.2 is vulnerable to Stored XSS in Board Custom Slot dialog. The customslot savetemplate endpoint authorizes the request only against the target board instance canEditBoardContents and then persists the client-supplied selectedTemplateOptioncollection verbatim,...

PT-2026-90498

Concrete CMS below 9.5.3 does not apply HTML output escaping to the file description and tags fields when rendering the Document Library block, so a user with permission to edit file properties could store a script payload that executed in the browser of any visitor to a page displaying the block...

CVE-2026-81917: Improper Neutralization of Input During Web Page Generation

Concrete CMS below 9.5.3 does not apply HTML output escaping to the file description and tags fields when rendering the Document Library block, so a user with permission to edit file properties could store a script payload that executed in the browser of any visitor to a page displaying the block...