PrefectGHSA-c635-393c-hcx2
Prefect has an Authentication Middleware Bypass when URL paths are appended with 'health' or 'ready'
High7.5CVE-2026-3514 · Published Jun 2, 2026 · updated Sep 10, 2026
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| prefect PyPI | < 3.6.22.dev7 | 3.6.22.dev7 |
Details and references
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.
- CVSS 3.0
- CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-863
- Also known as
- CVE-2026-3514, PYSEC-2026-2261
More Prefect advisories
All Prefect| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| May 26 | Prefect has an Argument Injection issue CVE-2026-3515High8.5no fix yet | High8.5 | No fix yet |
| May 4 | Prefect Git Argument Injection in GitRepository Pull Steps CVE-2026-7725Low6.3fixed in 3.6.25.dev7 | Low6.3 | 3.6.25.dev7 |
| May 4 | Prefect Auth Bypass via endswith() Health Check Exemption CVE-2026-7722Medium5.3fixed in 3.6.22 | Medium5.3 | 3.6.22 |
| May 4 | Prefect Unauthenticated Event Injection via /api/events/in WebSocket CVE-2026-7723Medium7.3fixed in 3.6.14 | Medium7.3 | 3.6.14 |
| May 4 | Prefect SSRF Bypass via DNS Rebinding in validate_restricted_url CVE-2026-7724Low5.0fixed in 3.6.28.dev2 | Low5.0 | 3.6.28.dev2 |
| Mar 202025 | Prefect CORS (Cross-Origin Resource Sharing) misconfiguration CVE-2024-8183High7.6fixed in 2.20.17, 3.0.3 | High7.6 | 2.20.17, 3.0.3 |