CVE-2024-35239

References

https://docs.umbraco.com/umbraco-forms/release-notes#id-13.0.1-january-16th-2024
https://docs.umbraco.com/umbraco-forms/v/12.forms.latest/release-notes#id-12.2.2-january-16th-2024
https://docs.umbraco.com/umbraco-forms/v/10.forms.latest/release-notes
https://docs.umbraco.com/umbraco-forms/developer/configuration#editing-configuration-values

Authenticated user that has access to edit Forms may inject unsafe code into Forms components.

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

CVE-2024-35239 has a CVSS score of 2.7 (Low). The vector is network-reachable, high privileges required, and no user interaction. 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 (13.0.1, 12.2.2, 10.5.3, 8.13.13); upgrading removes the vulnerable code path.

Kodem intelligence

Issue can be mitigated by configuring TitleAndDescription:AllowUnsafeHtmlRendering after upgrading to patched versions (13.0.1, 12.2.2, 10.5.3, 8.13.13).

1. What is CVE-2024-35239? CVE-2024-35239 is a low-severity cross-site scripting (XSS) vulnerability in Umbraco.Forms (nuget), affecting versions >= 13.0.0, < 13.0.1. It is fixed in 13.0.1, 12.2.2, 10.5.3, 8.13.13. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is CVE-2024-35239? CVE-2024-35239 has a CVSS score of 2.7 (Low). 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.Forms are affected by CVE-2024-35239? Umbraco.Forms (nuget) versions >= 13.0.0, < 13.0.1 is affected.
4. Is there a fix for CVE-2024-35239? Yes. CVE-2024-35239 is fixed in 13.0.1, 12.2.2, 10.5.3, 8.13.13. Upgrade to this version or later.
5. Is CVE-2024-35239 exploitable, and should I be worried? Whether CVE-2024-35239 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-2024-35239 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-2024-35239?
   • Upgrade Umbraco.Forms to 13.0.1 or later
   • Upgrade Umbraco.Forms to 12.2.2 or later
   • Upgrade Umbraco.Forms to 10.5.3 or later
   • Upgrade Umbraco.Forms to 8.13.13 or later

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