Concrete CMS below 9.5.3 was vulnerable to Cross-Site Request Forgery in the dashboard SEO Excluded Words page. (CVE-2026-81920)
Concrete CMS versions below 9.5.3 contain a Cross-Site Request Forgery (CSRF) vulnerability in the dashboard SEO Excluded Words page. The reset() controller action that clears the reserved-word list does not validate the anti-CSRF token and does not restrict the request to POST, allowing an attacker to revert the reserved-word list to default silently. This could alter future URL slug generation, undoing the site's SEO slug policy. The vulnerability has a low severity score of 2.3 according to the Concrete CMS security team.
AI Analysis
Technical Summary
Concrete CMS prior to version 9.5.3 is vulnerable to CSRF in the dashboard SEO Excluded Words page. The reset() controller action fails to validate the anti-CSRF token and does not restrict the HTTP method, enabling an attacker to cause an authenticated SEO user to reset the reserved-word list to its default. This affects the URL slug generation for pages, files, topics, and other objects created via the Text urlify service, undoing the site's configured SEO slug policy. The vulnerability has a CVSS v4.0 base score of 2.3, indicating low severity.
Potential Impact
An attacker can cause an authenticated user with SEO access to reset the reserved-word list silently, which may alter future URL slug generation and undo SEO slug policies configured on the site. This could impact SEO consistency but does not directly compromise confidentiality, integrity, or availability of the system.
Mitigation Recommendations
A fix is available in Concrete CMS version 9.5.3 and later. Users should upgrade to version 9.5.3 or above to remediate this vulnerability. Until then, restricting access to the SEO Excluded Words page and ensuring users do not visit untrusted pages while authenticated can reduce risk.
Concrete CMS below 9.5.3 was vulnerable to Cross-Site Request Forgery in the dashboard SEO Excluded Words page. (CVE-2026-81920)
Description
Concrete CMS versions below 9.5.3 contain a Cross-Site Request Forgery (CSRF) vulnerability in the dashboard SEO Excluded Words page. The reset() controller action that clears the reserved-word list does not validate the anti-CSRF token and does not restrict the request to POST, allowing an attacker to revert the reserved-word list to default silently. This could alter future URL slug generation, undoing the site's SEO slug policy. The vulnerability has a low severity score of 2.3 according to the Concrete CMS security team.
CVSS v4.0
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Concrete CMS prior to version 9.5.3 is vulnerable to CSRF in the dashboard SEO Excluded Words page. The reset() controller action fails to validate the anti-CSRF token and does not restrict the HTTP method, enabling an attacker to cause an authenticated SEO user to reset the reserved-word list to its default. This affects the URL slug generation for pages, files, topics, and other objects created via the Text urlify service, undoing the site's configured SEO slug policy. The vulnerability has a CVSS v4.0 base score of 2.3, indicating low severity.
Potential Impact
An attacker can cause an authenticated user with SEO access to reset the reserved-word list silently, which may alter future URL slug generation and undo SEO slug policies configured on the site. This could impact SEO consistency but does not directly compromise confidentiality, integrity, or availability of the system.
Mitigation Recommendations
A fix is available in Concrete CMS version 9.5.3 and later. Users should upgrade to version 9.5.3 or above to remediate this vulnerability. Until then, restricting access to the SEO Excluded Words page and ensuring users do not visit untrusted pages while authenticated can reduce risk.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-5fv5-37wq-24h2
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-81920"]
- Database Specific Severity
- LOW
- Cvss Version
- 4.0
Threat ID: 6aaa07ea55bf5e2cf5ea3d37
Added to database: 09/16/2026, 03:07:22 UTC
Last enriched: 09/16/2026, 04:58:42 UTC
Last updated: 09/16/2026, 22:01:39 UTC
Views: 2
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