Concrete CMS below 9.5.3 is vulnerable to Stored XSS via unsanitized inline block custom style values

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Affected scope and exposure questions

The current feed maps Concrete CMS/Concrete CMS (generic). Check affected ranges and fixed versions before updating.

Recommended response

1. 1Check inventory. Check lockfiles and deployed manifests for Concrete CMS/Concrete CMS.
2. 2Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

1. Published upstream

   Sep 14, 2026

   Evidence: source:cvelist:source_dates:source-dates:record

2. Source modified

   Sep 14, 2026

   Evidence: source:cvelist:source_dates:source-dates:record

3. First seen by HOL

   Sep 14, 2026

Sources and claim methodology

• Source referencedocumentation.concretecms.org

Related CVEs

• Concrete CMS 9.2.0 to 9.5.2 is vulnerable to stored XSS due to missing authorization in the `PUT /pages/{cID}` endpointSame concrete cms/concrete cms package
• Concrete CMS 9.0.0 to 9.5.2 is vulnerable to CSRF on Orphan Block CleanupSame concrete cms/concrete cms package
• Concrete CMS 9.0.0 to 9.5.2 is vulnerable to Stored XSS via Page Container iconSame concrete cms/concrete cms package
• Security vulnerabilities have been addressed in IBM Verify Identity Access and IBM Security Verify AccessAlso CWE-79
• IBM WebSphere Application Server prior to 9.0.5.29 and 8.5.5.31 are affected by multiple vulnerabilitiesAlso CWE-79
• Langflow is vulnerable to authentication bypass and insufficient session expirationSame generic ecosystem