CVE-2026-18422

Concrete CMS below 9.5.3 Multilingual Page Assign Action Lacks Destination Authorization and CSRF Token Validation

MEDIUM
6.5
CVSS Score
Published: September 15, 2026 at 07:27 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 0.5%
SSVC
No known exploit

Description

Concrete CMS before 9.5.3 did not enforce a destination-side authorization check and did not validate a CSRF token in the multilingual page assignment backend action (Backend\Page\Multilingual::assign). As a result, an authenticated user who held the Edit Page Multilingual Settings permission on a single page could bind an arbitrary page in another locale as that source page's translation, and could delete legitimate translation pairs maintained by other editors, altering public-facing language routing across the site. 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:L/SC:N/SI:N/SA:N. Thanks Winston Crooker 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
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-862

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