CVE-2026-53656 FiftyOne App server uses wildcard CORS (Access-Control-Allow-Origin: *), enabling cross-origin reads of local server data
A malicious website can read local FiftyOne server data and files due to wildcard CORS settings, exposing sensitive information to drive-by attackers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-53656?
CVE-2026-53656 is a medium-severity vulnerability in voxel51 fiftyone, published on 21 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2026-53656?
3 open source packages ship an affected version, including fiftyone.
| Package | Affected | Fixed in |
|---|---|---|
fiftyone PyPI | All versions | 1.17.0 |
fiftyone PyPI | All versions | 1.17.0 |
fiftyone PyPI | All versions | 1.17.0 |
How do I fix CVE-2026-53656?
Upgrade fiftyone to 1.17.0 or later.
Is CVE-2026-53656 being exploited?
There is no known exploitation of CVE-2026-53656 in the wild and no public exploit code.
Sources
Also known as GHSA-q78p-hj9h-5466, PYSEC-2026-3465.