CVEvulnerability

CVE-2026-18426

2.0 LOW Published 2026-09-15 Modified 2026-09-21 Official page ↗
Status
Analyzed
Published
2026-09-15
Last modified
2026-09-21
Assigner
ff5b8ace-8b95-4078-9743-eac1ca5451de
CVSS 4.0 (ff5b8ace-8b95-4078-9743-eac1ca5451de)
2.0 LOW — CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1 ([email protected])
6.5 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Weaknesses
CWE-862

Description

Concrete CMS 9.0.0 through 9.5.2 did not enforce a block-level edit-permission check on the Express Form block's control-management actions, which relied solely on CSRF token validation. Because the token is bound to the user and action rather than to a specific block, page, or form, an authenticated user with edit access to one Express Form could reuse a validly obtained token to add, modify, or delete controls on Express Forms they were not authorized to edit, including injecting a control whose value is later rendered as HTML to achieve stored XSS. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.0 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Yat Wu for reporting.

Affected configurations

• concretecms concrete cms (>= 9.0.0 < 9.5.3)

Related

Weakness · CWE (1)

  • CWE-862 Missing Authorization weakness

References