# CVE-2026-3514: Prefect authentication bypass via health check path exemption

Source: https://junglewise.ai/threats/cve-2026-3514-prefect-authentication-bypass-via-health-check-path-exemption  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-02. Updated: 2026-07-09  
License: CC BY 4.0 with a link back

CVE-2026-3514 · Severity: high · CVSS 7.5 · Published 2026-06-02

Prefect, a workflow orchestration platform, contains a security flaw that allows unauthorized users to bypass authentication. By naming resources like variables or deployments with specific suffixes such as 'health' or 'ready', an attacker can access them without a password. This could lead to the theft of sensitive business data, including API keys and database credentials stored within the system.

Technologies: [prefect (PyPI)](https://junglewise.ai/threats/technologies/prefect). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-3514 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-3514 being exploited in the wild.

**How severe is CVE-2026-3514?** High severity, with a CVSS score of 7.5, published 2 June 2026.

**Which products and versions are affected?** prefect (PyPI) < 3.6.22.dev7, ECOSYSTEM:introduced=0,fixed=3.6.22, ECOSYSTEM:introduced=0,fixed=3.6.22.dev7.

**Is there a fix for CVE-2026-3514?** Yes. prefect (PyPI): upgrade to 3.6.22, 3.6.22.dev7 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-3514 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-3514?** Check whether you run prefect (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- prefect (PyPI): upgrade to 3.6.22, 3.6.22.dev7 or later

  ```sh
  pip install "prefect>=3.6.22.dev7"
  ```


## Technical details

An authentication bypass vulnerability exists in Prefect's server middleware due to improper path validation for health check exemptions. The middleware uses a suffix-based check (endswith) that exempts any URL ending in 'health' or 'ready' from authentication. An unauthenticated remote attacker can exploit this by creating or accessing resources (such as Variables, Flows, or Deployments) whose names end with these strings. Successful exploitation allows unauthorized access to sensitive data stored in Prefect Variables, including credentials and API keys. The issue is addressed in version 3.6.22.dev7 by tightening the path matching logic.

## Affected products

- PrefectHQ Prefect < 3.6.22.dev7

## Identifiers

- CVE-2026-3514
- GHSA-c635-393c-hcx2
- PYSEC-2026-2261

## Timeline

- 2026-06-02: disclosed
- 2026-06-02: advisory
- 2026-07-09: patched

## References

- [https://github.com/prefecthq/prefect/commit/e21617125335025b4b27e7d6f0ca028e8e8f3b79](https://github.com/prefecthq/prefect/commit/e21617125335025b4b27e7d6f0ca028e8e8f3b79)
- [https://huntr.com/bounties/c540e5e1-f74f-44f4-bfa0-9764ff6daa75](https://huntr.com/bounties/c540e5e1-f74f-44f4-bfa0-9764ff6daa75)

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- [PYSEC-2026-1799 - Cross-Site Request Forgery vulnerability in Prefect](https://junglewise.ai/threats/cve-2023-6022-cross-site-request-forgery-vulnerability-in-prefect)
- [Prefect remote code execution in GitRepository storage class](https://junglewise.ai/threats/cve-2026-5366-prefect-remote-code-execution-in-gitrepository-storage-class)
- [Prefect prefect-github argument injection in GitHubRepository](https://junglewise.ai/threats/cve-2026-3515-prefect-prefect-github-argument-injection-in-githubrepository)
- [Prefect Git argument injection in GitRepository Pull Handler](https://junglewise.ai/threats/cve-2026-7725-prefect-git-argument-injection-in-gitrepository-pull-handler)