High severity · published Sep 14, 2026
CVE-2026-81902
Concrete CMS 9.0.0 to 9.5.2 is vulnerable to CSRF on Orphan Block Cleanup
8.1
CVSS
0.2%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 15% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CC
Concrete CMS · Concrete CMS
9.0.0 through 9.5.2 · source: vendor, NVD
Affected product
CC
Concrete CMS
Concrete CMS
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