TI-2026-03027 Aliases CVE-2026-3514 GHSA-c635-393c-hcx2

Authentication Bypass in prefecthq/prefect

HIGH 72CWE-863Published 2026-06-02 · Updated 2026-06-02

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Security bypass
Confidentiality · integrity · availability: High · None · None
Fix status: Fixed

Attack profile from CVSS 3.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-863.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00476 41st percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed prefecthq/prefect (prefecthq): 3.6.22prefect (PyPI): 3.6.22.dev7

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
PrefectHQ	prefecthq/prefect	before 3.6.22	3.6.22	Patch available	CNA
—	prefect (PyPI)	before 3.6.22.dev7	3.6.22.dev7	Patch available	GHSA-c635-393c-hcx2

prefecthq/prefect VendorPrefectHQ Affected before 3.6.22 Fixed in 3.6.22 Patch available CNA
prefect (PyPI) Vendor— Affected before 3.6.22.dev7 Fixed in 3.6.22.dev7 Patch available GHSA-c635-393c-hcx2

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:prefect:prefect::::::::	before 3.6.22	Vulnerable	PrefectHQ

cpe:2.3:a:prefect:prefect:*:*:*:*:*:*:*:* Versions before 3.6.22 Vulnerable ·PrefectHQ

Remediation

Fix · CNA prefecthq/prefect (prefecthq) Fixed in 3.6.22
Fix · GHSA-c635-393c-hcx2 prefect (PyPI) Fixed in 3.6.22.dev7 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-3514
2026-10-03 Alias added: GHSA-c635-393c-hcx2

References

TI-2026-04695 Git Argument Injection in prefecthq/prefect CVSS 3.0CRITICAL 9.9
TI-2023-05548 Cross-Site Request Forgery (CSRF) in prefecthq/prefect CVSS 3.1HIGH 8.8

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences