CVEvulnerability

CVE-2026-81913

5.3 MEDIUM Published 2026-09-11 Modified 2026-09-24 Official page ↗
Status
Analyzed
Published
2026-09-11
Last modified
2026-09-24
Assigner
ff5b8ace-8b95-4078-9743-eac1ca5451de
CVSS 4.0 (ff5b8ace-8b95-4078-9743-eac1ca5451de)
5.3 MEDIUM — CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/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])
6.1 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weaknesses
CWE-601

Description

Concrete CMS versions 9.5.0 through 9.5.2 are vulnerable to Open Redirect via the rcURL parameter. An attacker can craft a single link on the site's own domain that sends a user to an arbitrary external site immediately after authentication, facilitating phishing and credential theft. The same handling is present in the registration flow, giving a second entry point on sites with registration enabled. Concrete CMS versions prior to 9.5.0 do not include the rcURL parameter or this allowlist and are not affected. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.3 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Michal M. for reporting.

Affected configurations

• concretecms concrete cms (>= 9.5.0 < 9.5.3)

Related

Weakness · CWE (1)

  • CWE-601 URL Redirection to Untrusted Site weakness

References