CVE-2026-28415 is a medium-severity (CVSS 4.3) Information Exposure vulnerability in gradio. A fix is available for gradio — see the affected versions and patch details below.
Gradio has Open Redirect in OAuth Flow
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-28415.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-28415 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
gradioReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
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.
Impact
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | gradio | all versions | 6.6.0pip install --upgrade 'gradio==6.6.0' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gradio, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update gradio to 6.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-28415 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-28415 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-28415. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-28415 in your dependencies?
O3 Security finds CVE-2026-28415 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.