CVE-2026-27167
Gradio: Mocked OAuth Login Exposes Server Credentials and Uses Hardcoded Session Secret
Description
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.
INFO
Published Date :
Feb. 27, 2026, 10:16 p.m.
Last Modified :
Feb. 27, 2026, 10:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-27167
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | NONE | [email protected] | ||||
| CVSS 3.1 | NONE | MITRE-CVE |
Solution
- Update Gradio to version 6.6.0 or later.
- Remove the use of OAuth components if unable to update.
- Restrict network access to the Gradio application.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-27167.
| URL | Resource |
|---|---|
| https://github.com/gradio-app/gradio/security/advisories/GHSA-h3h8-3v2v-rg7m |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-27167 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-27167
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-27167 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-27167 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Feb. 27, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:N Added CWE CWE-798 Added CWE CWE-522 Added Reference https://github.com/gradio-app/gradio/security/advisories/GHSA-h3h8-3v2v-rg7m