Read the docs
TI-2026-56531 Aliases CVE-2026-81920GHSA-5fv5-37wq-24h2

Cross-site request forgery in Concrete CMS

Priority LOW 11CWE-352Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
Present
Impact type
Tampering
Confidentiality · integrity · availability
None · Low · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-352.

Summary

Concrete CMS below 9.5.3 was vulnerable to Cross-Site Request Forgery in the dashboard SEO Excluded Words page. The reset() controller action cleared the administrator-configured reserved-word list (concrete.seo.exclude_words) but did not validate the anti-CSRF token that the reset modal emitted, and it did not restrict the request to the POST method. A remote attacker who lured an authenticated user with SEO access to a crafted page could revert the reserved-word list to its default and silently alter future URL-slug generation for pages, files, topics, and other objects created through the Text urlify service, undoing the site's configured SEO slug policy. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks riodrwn for reporting.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00177 7th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

No affected products listed by the sources yet.

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*before 9.5.3VulnerableConcrete CMS
  • cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:* Versions before 9.5.3 Vulnerable ·Concrete CMS

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-81920
  2. 2026-10-03 Alias added: GHSA-5fv5-37wq-24h2

References

Other 1

  • TI-2026-23602 ConcreteCMS v9.4.7 contains a Denial of Service (DoS) vulnerability in the File Manager… CVSS 3.1MEDIUM 6.5
  • TI-2023-23992 A Cross Site Scripting (XSS) vulnerability in Concrete CMS from versions 9.2.0 to 9.2.2… CVSS 3.1MEDIUM 5.4
  • TI-2023-26495 Concrete CMS before 8.5.13 and 9.x before 9.2.2 allows unauthorized access because… CVSS 3.1CRITICAL 9.8
  • TI-2026-14907 Missing authorization in Concrete CMS CVSS 4.0HIGH 8.7
  • TI-2022-06200 Cleartext transmission of sensitive information in https://github.com/concrete5/concrete5 CVSS 3.1CRITICAL 9.8
  • TI-2021-17294 An issue was discovered in Concrete CMS through 8.5.5. CVSS 3.1CRITICAL 9.8
See all 197 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences