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CVE-2026-27167PYSEC-2026-63GHSA-H3H8-3V2V-RG7M

Gradio: Mocked OAuth Login Exposes Server Credentials and Uses Hardcoded Session Secret

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 6.6.0
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: no
  • Technical impact: partial

Summary

Gradio is an open-source Python package designed for quick prototyping. Starting in version 4.16.0 and prior to version 6.6.0, Gradio applications running outside of Hugging Face Spaces automatically enable "mocked" OAuth routes when OAuth components (e.g. `gr.LoginButton`) are used. When a user visits `/login/huggingface`, the server retrieves its own Hugging Face access token via `huggingface_hub.get_token()` and stores it in the visitor's session cookie. If the application is network-accessible, any remote attacker can trigger this flow to steal the server owner's HF token. The session cookie is signed with a hardcoded secret derived from the string `"-v4"`, making the payload trivially decodable. Version 6.6.0 fixes the issue.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • gradio-app gradio

    From 4.16.0 · fixed in 6.6.0

  • gradioPyPI

    From 4.16.0 · fixed in 6.6.0

References 1

GitHub · gradio-app/gradio