CVE-2026-81924

Concrete CMS below 9.5.3 is vulnerable to Cross-Site Request Forgery (CSRF) in Theme Page Template Activation

MEDIUM
6.5
CVSS Score
Published: September 15, 2026 at 06:55 PM UTC
Updated: September 21, 2026 at 06:05 PM UTC
1 product affected across 1 vendorConcrete CMS

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

Concrete CMS before 9.5.3 is vulnerable to Cross-Site Request Forgery (CSRF) in the theme page-template activation feature. The Dashboard theme Inspect controller's activate_files() action created PageTemplate records from attacker-supplied pageTemplates[] values without validating an anti-CSRF token.A remote attacker could host a page that auto-submitted a forged POST request; when a signed-in administrator visited it, the request executed under the administrator's session and created theme page-template records, changing site configuration without the administrator's consent. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.1 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Andrew Gonzalez for reporting.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 9.5.35.0.0 ≤ v ≤ 9.5.25.0.0
Affected range stops below 9.5.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-352

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