CVE-2026-81913 (GCVE-0-2026-81913)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:30 – Updated: 2026-09-11 19:36
VLAI
Title
Concrete CMS versions 9.5.0 through 9.5.2 are vulnerable to Open Redirect via the rcURL parameter.
Summary
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.
Severity
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
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-11 19:35 UTC
CWE
  • CWE-601 - URL redirection to untrusted site ('open redirect')
Assigner
ConcreteCMS CNA under the mitre root
CNA scorecard B 84/100 over 111 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Concrete CMS Concrete CMS Affected: 9.5.0 , ≤ 9.5.2 (git)
guessed Create a notification for this product.
Credits
braintxx
Show details on NVD website
To clipboard 

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