CVE-2026-81918

Concrete CMS below 9.5.3 is vulnerable to Stored XSS via the Date Format field in the Page Attribute Display block

MEDIUM
4.8
CVSS Score
Published: September 11, 2026 at 08:19 PM UTC
Updated: September 18, 2026 at 03:19 PM UTC
1 product affected across 1 vendorConcrete CMS

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Severity
MEDIUM4.8
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

Concrete CMS below 9.5.3 is vulnerable to Stored XSS via the Date Format field in the Page Attribute Display block. A user with edit_page_contents permissions could store a payload which executes in the browser of any visitor who viewed a page where the block was configured to display a date-type attribute. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 4.8 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Oriol Ortiz 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

4.8MEDIUMConcreteCMS
Vector?

Quick Info

StatusANALYZED
CWE
CWE-79

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