CVE-2026-53656

Received Received - Intake

Cross-Origin Resource Sharing (CORS) Misconfiguration in FiftyOne

Publication date: 2026-08-21

Last updated on: 2026-08-21

Assigner: GitHub, Inc.

Description

FiftyOne is an open-source platform for refining high-quality datasets and visual AI models. Prior to 1.17.0, the FiftyOne App/API server in fiftyone/server/app.py and the /media route in fiftyone/server/routes/media.py unconditionally return Access-Control-Allow-Origin: *. Because the embedded server is local and unauthenticated, a malicious website visited by the user can read cross-origin responses. The /media endpoint accepts a filesystem path, allowing a drive-by page to read files accessible to the server process and exfiltrate them without additional clicks. The allowed_origins configuration and FIFTYONE_ALLOWED_ORIGINS environment variable now make cross-origin access explicit, while the default policy is same-origin. This issue is fixed in version 1.17.0.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-08-21

Last Modified

2026-08-21

Generated

2026-08-22

AI Q&A

2026-08-22

EPSS Evaluated

N/A

NVD

CVE-2026-53656

Affected Vendors & Products

Vendor	Product	Version / Range
fiftyone	fiftyone	to 1.17.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-942	The product uses a web-client protection mechanism such as a Content Security Policy (CSP) or cross-domain policy file, but the policy includes untrusted domains with which the web client is allowed to communicate.
CWE-346	The product does not properly verify that the source of data or communication is valid.

Attack-Flow Graph

Executive Summary

This vulnerability is a cross-origin resource sharing (CORS) issue in FiftyOne versions before 1.17.0. The server unconditionally allows all origins to access resources via the Access-Control-Allow-Origin: * header. Since the server runs locally and without authentication, a malicious website can exploit this to read files on the user's system through the /media endpoint, which accepts filesystem paths.

Detection Guidance

Check the FiftyOne server version with pip show fiftyone. If it is below 1.17.0, the system is vulnerable. Inspect network traffic for cross-origin requests to the /media endpoint or unusual file access patterns.

Impact Analysis

If you use FiftyOne before version 1.17.0, a malicious website you visit could silently access files on your system that the FiftyOne server can read. This could lead to unauthorized data exposure or theft of sensitive files without requiring additional user interaction.

Compliance Impact

This vulnerability could lead to unauthorized data access, potentially violating GDPR (data protection) and HIPAA (health information privacy) by exposing sensitive or personal data. Compliance may be compromised if unauthorized access occurs due to insufficient access controls.

Mitigation Strategies

Upgrade FiftyOne to version 1.17.0 or later. If upgrading is not possible, restrict the server to same-origin access by setting allowed_origins or FIFTYONE_ALLOWED_ORIGINS to explicit trusted origins.

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