CVE-2026-3514 Authentication Bypass in prefecthq/prefect
Attackers can bypass authentication by accessing endpoints with names ending in 'health' or 'ready', exposing sensitive data like API keys.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-3514?
CVE-2026-3514 is a high-severity authentication bypass vulnerability in prefecthq/prefect, published on 2 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-863
Which versions are affected by CVE-2026-3514?
3 open source packages ship an affected version, including prefect. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
prefect PyPI | All versions | 3.6.22 |
prefect PyPI | All versions | 3.6.22.dev7 |
prefect PyPI | All versions | 3.6.22.dev7 |
Products include Prefect Prefect.
How do I fix CVE-2026-3514?
Upgrade prefect to a fixed version for your release line: 3.6.22 or 3.6.22.dev7.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-3514 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3514 exists.
Other vulnerabilities in prefecthq/prefect
Sources
Also known as GHSA-c635-393c-hcx2, PYSEC-2026-2261, ROOT-APP-PYPI-CVE-2026-3514.