---
id: CVE-2026-3514
aliases:
  - GHSA-c635-393c-hcx2
  - PYSEC-2026-2261
title: >-
  Prefect has an Authentication Middleware Bypass when URL paths are appended
  with 'health' or 'ready'
summary: >-
  Prefect has an Authentication Middleware Bypass when URL paths are appended
  with 'health' or 'ready'
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
vendor: prefect
product: prefect
ecosystem: pip
affected:
  - prefect < 3.6.22.dev7
patched:
  - prefect 3.6.22.dev7
published: '2026-06-02'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:51:08.407849486Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-c635-393c-hcx2'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-3514'
  - url: >-
      https://github.com/prefecthq/prefect/commit/e21617125335025b4b27e7d6f0ca028e8e8f3b79
  - url: 'https://github.com/PrefectHQ/prefect'
  - url: 'https://huntr.com/bounties/c540e5e1-f74f-44f4-bfa0-9764ff6daa75'
tags:
  - osv
  - pip
epss: 0.00476
epssPercentile: 0.40282
ingestedAt: '2026-07-10T13:49:10.703Z'
---

## Overview

In version 3.6.19 of prefecthq/prefect, an authentication bypass vulnerability exists due to the improper handling of URL path exemptions for health check probes. Specifically, the authentication middleware exempts any URL path ending with 'health' or 'ready' from authentication checks. This allows an attacker to create resources with names ending in 'health' or 'ready' and access them without authentication. Affected endpoints include those for variables, flows, work pools, work queues, and deployments. This vulnerability can lead to unauthorized access to sensitive information, such as API keys and database credentials, stored in Prefect Variables.

## Affected packages

- `prefect < 3.6.22.dev7`

## Remediation

Upgrade to a patched release:

- `prefect 3.6.22.dev7`