CVE-2026-46616

Umbraco.Cms: Open Redirect Vulnerability in Surface Controllers

  @using (Html.BeginUmbracoForm<UmbLoginStatusController>(
      "HandleLogout",
      new { RedirectUrl = Model.Url() }))
  {
      <button type="submit">Log out</button>
  }

Some of the Surface Controllers in the CMS provide to support member related operations fail to validate redirect URLs, making Razor templates that derive 'RedirectUrl' from user-controlled query parameters vulnerable to malicious redirect attacks.

Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites. Typical impact: phishing and credential harvesting via a trusted domain.

CVE-2026-46616 has a CVSS score of 5.4 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (13.14.0, 17.4.0); upgrading removes the vulnerable code path.

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The issue is resolved in versions 17.4.0 and 13.14.0.

1. What is CVE-2026-46616? CVE-2026-46616 is a medium-severity open redirect vulnerability in Umbraco.Cms (nuget), affecting versions < 13.14.0. It is fixed in 13.14.0, 17.4.0. Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites.
2. How severe is CVE-2026-46616? CVE-2026-46616 has a CVSS score of 5.4 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of Umbraco.Cms are affected by CVE-2026-46616? Umbraco.Cms (nuget) versions < 13.14.0 is affected.
4. Is there a fix for CVE-2026-46616? Yes. CVE-2026-46616 is fixed in 13.14.0, 17.4.0. Upgrade to this version or later.
5. Is CVE-2026-46616 exploitable, and should I be worried? Whether CVE-2026-46616 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-46616 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-46616?
   • Upgrade Umbraco.Cms to 13.14.0 or later
   • Upgrade Umbraco.Cms to 17.4.0 or later

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