CVE-2026-28415

The _redirect_to_target() function in Gradio's OAuth flow accepts an unvalidated _target_url query parameter, allowing redirection to arbitrary external URLs. This affects the /logout and /login/callback endpoints on Gradio apps with OAuth enabled (i.e. apps running on Hugging Face Spaces with gr.LoginButton).

Details

  def _redirect_to_target(request, default_target="/"):
      target = request.query_params.get("_target_url", default_target)
      return RedirectResponse(target)  # No validation

An attacker can craft a URL like https://my-space.hf.space/logout?_target_url=https://evil.com/phishing that redirects the user to an external site after logout. Because the URL originates from a trusted hf.space domain, users are more likely to trust the link.

Phishing, an attacker can use the trusted domain to redirect users to a malicious site. No direct data exposure or server-side impact.

Fix

The _target_url parameter is now sanitized to only use the path, query, and fragment, stripping any scheme or host.

Security-sensitive operations rely on values that are predictable or insufficiently random. Typical impact: forged tokens, guessable identifiers, or broken cryptographic protocols.

CVE-2026-28415 has a CVSS score of 4.3 (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 (6.6.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-28415? CVE-2026-28415 is a medium-severity use of insufficiently random values vulnerability in gradio (pip), affecting versions < 6.6.0. It is fixed in 6.6.0. Security-sensitive operations rely on values that are predictable or insufficiently random.
2. How severe is CVE-2026-28415? CVE-2026-28415 has a CVSS score of 4.3 (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 gradio are affected by CVE-2026-28415? gradio (pip) versions < 6.6.0 is affected.
4. Is there a fix for CVE-2026-28415? Yes. CVE-2026-28415 is fixed in 6.6.0. Upgrade to this version or later.
5. Is CVE-2026-28415 exploitable, and should I be worried? Whether CVE-2026-28415 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-2026-28415 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-2026-28415? Upgrade gradio to 6.6.0 or later.