EUVD-2026-76243

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...

CVE-2026-81911 Concrete CMS versions 9.0.0 to 9.5.2 is vulnerable to Stored XSS in Board Custom Slot save_template via Unescaped Summary Description

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,...

CVE-2026-81911

Concrete CMS versions 9.0.0 through 9.5.2 contain a Stored XSS in the Board Custom Slot dialog. The custom_slot save_template endpoint authorizes requests only against the target board instance via canEditBoardContents() but persists the client-supplied selectedTemplateOption[collection] verbatim...

EUVD-2026-76447

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,...

CVE-2026-81911 Concrete CMS versions 9.0.0 to 9.5.2 is vulnerable to Stored XSS in Board Custom Slot save_template via Unescaped Summary Description

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,...

CVE-2026-81911 Concrete CMS versions 9.0.0 to 9.5.2 is vulnerable to Stored XSS in Board Custom Slot save_template via Unescaped Summary Description

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,...

CVE-2026-53952

GetSimple CMS (v3.4.0a and below) and GetSimpleCMS-CE (v3.3.22 and below) are affected by a logic flaw that allows unauthenticated attackers to create a new administrator account . The root cause is a self-exclusion bug in the post-installation deletion logic for admin/setup.php, which fails to r...

EUVD-2026-76446

GetSimple CMS is a content management system CMS, and GetSimple CMS CE is the community edition of that CMS. A logic flaw in GetSimple CMS v3.4.0a and below and GetSimpleCMS-CE v3.3.22 and below allows unauthenticated attackers to create a new administrator account. The application features an...

CVE-2026-53952 GetSimple CMS & GetSimpleCMS-CE have an Unauthenticated Admin Account Creation via Setup Logic Flaw

GetSimple CMS is a content management system CMS, and GetSimple CMS CE is the community edition of that CMS. A logic flaw in GetSimple CMS v3.4.0a and below and GetSimpleCMS-CE v3.3.22 and below allows unauthenticated attackers to create a new administrator account. The application features an...

CVE-2026-53952 GetSimple CMS & GetSimpleCMS-CE have an Unauthenticated Admin Account Creation via Setup Logic Flaw

GetSimple CMS is a content management system CMS, and GetSimple CMS CE is the community edition of that CMS. A logic flaw in GetSimple CMS v3.4.0a and below and GetSimpleCMS-CE v3.3.22 and below allows unauthenticated attackers to create a new administrator account. The application features an...

CVE-2026-53952 GetSimple CMS & GetSimpleCMS-CE have an Unauthenticated Admin Account Creation via Setup Logic Flaw

GetSimple CMS is a content management system CMS, and GetSimple CMS CE is the community edition of that CMS. A logic flaw in GetSimple CMS v3.4.0a and below and GetSimpleCMS-CE v3.3.22 and below allows unauthenticated attackers to create a new administrator account. The application features an...

CVE-2026-81910

Concrete CMS 9 through 9.5.2 is vulnerable to Server-Side Template Injection SSTI in Theme Customizer via Unvalidated Style Values. Values submitted through the customizer color channels and other style properties handled by ColorStyle and sibling Style classes such as FontFamilyStyle and...

CVE-2026-81910

Concrete CMS 9 through 9.5.2 is vulnerable to Server-Side Template Injection (SSTI) in the Theme Customizer . Style values handled by classes such as ColorStyle, FontFamilyStyle, and ImageStyle are interpolated into server-compiled LESS source without neutralizing LESS syntax. An attacker with th...

EUVD-2026-76193

Concrete CMS 9 through 9.5.2 is vulnerable to Server-Side Template Injection SSTI in Theme Customizer via Unvalidated Style Values. Values submitted through the customizer color channels and other style properties handled by ColorStyle and sibling Style classes such as FontFamilyStyle and...

CVE-2026-81910 Concrete CMS 9 through 9.5.2 is vulnerable to Server-Side Template Injection (SSTI) in Theme Customizer via Unvalidated Style Values

Concrete CMS 9 through 9.5.2 is vulnerable to Server-Side Template Injection SSTI in Theme Customizer via Unvalidated Style Values. Values submitted through the customizer color channels and other style properties handled by ColorStyle and sibling Style classes such as FontFamilyStyle and...

CVE-2026-81910 Concrete CMS 9 through 9.5.2 is vulnerable to Server-Side Template Injection (SSTI) in Theme Customizer via Unvalidated Style Values

Concrete CMS 9 through 9.5.2 is vulnerable to Server-Side Template Injection SSTI in Theme Customizer via Unvalidated Style Values. Values submitted through the customizer color channels and other style properties handled by ColorStyle and sibling Style classes such as FontFamilyStyle and...

CVE-2026-81910 Concrete CMS 9 through 9.5.2 is vulnerable to Server-Side Template Injection (SSTI) in Theme Customizer via Unvalidated Style Values

Concrete CMS 9 through 9.5.2 is vulnerable to Server-Side Template Injection SSTI in Theme Customizer via Unvalidated Style Values. Values submitted through the customizer color channels and other style properties handled by ColorStyle and sibling Style classes such as FontFamilyStyle and...

CVE-2026-81908

Concrete CMS 9.2.0 to 9.5.2 contain a missing authorization vulnerability in the REST API Groups list endpoint. The listGroups method in concrete/src/Api/Controller/Groups.php registers a permissions checker callback that unconditionally returns true, so no per-object tree node authorization is...

CVE-2026-81909

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...

CVE-2026-68528

Concrete CMS RSS Displayer block below version 9.5.3 rendered remote feed item titles without HTML escaping, resulting in stored cross-site scripting. An attacker able to control a title in a syndicated feed could execute script in the site origin for any visitor to the affected page, including...