Vulnerability · Published Feb 27, 2026 · Assigned by GitHub_M

CVE-2026-27167Gradio: Mocked OAuth Login Exposes Server Credentials and Uses Hardcoded Session Secret

None 0.0

In plain English

A hard-coded credentials in gradio from gradio-app. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)0.0None

Exploit odds (30 days)0.5%top 56.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	gradio	6.6.0	GHSA-h3h8-3v2v-rg7m
PyPI	gradio	6.6.0	PYSEC-2026-63

Affected products (as reported)

Vendor	Product	Versions
gradio-app	gradio	>= 4.16.0, < 6.6.0

Weakness: CWE-798, CWE-522 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:N

References

https://github.com/gradio-app/gradio/security/advisories/GHSA-h3h8-3v2v-rg7m x_refsource_CONFIRM