Vulnerability Description
Concrete CMS 9 through 9.5.2 did not validate a CSRF token in the orphaned block removal panel action (removeOrphanedBlocks). A remote attacker could craft a request that, when loaded by an authenticated user holding edit permission on the target page, deleted every block on that page's current version; blocks not aliased to another page or scrapbook entry were also removed from the global Blocks table and their block-type data table, permanently destroying the content. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.1 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Concretecms | Concrete Cms | >= 9.0.0, < 9.5.3 |
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-81902?
CVE-2026-81902 is a vulnerability with a CVSS score of 8.1 (HIGH). Concrete CMS 9 through 9.5.2 did not validate a CSRF token in the orphaned block removal panel action (removeOrphanedBlocks). A remote attacker could craft a request that, when loaded by an authentica...
How severe is CVE-2026-81902?
CVE-2026-81902 has been rated HIGH with a CVSS base score of 8.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-81902?
Check the references section above for vendor advisories and patch information. Affected products include: Concretecms Concrete Cms.