# 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.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Jun 2026
- **Updated:** 2 Jun 2026
- **Also known as:** GHSA-c635-393c-hcx2, PYSEC-2026-2261, ROOT-APP-PYPI-CVE-2026-3514

## 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 (Incorrect Authorization)

## Which versions are affected by CVE-2026-3514?

3 open source packages ship an affected version, including prefect. It affects 1 product.


| Package | Ecosystem | 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: 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.

## 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

- [CVE-2026-5366](https://insights.sbomify.com/CVE-2026-5366/): Git Argument Injection in prefecthq/prefect (critical 9.9)
- [CVE-2023-6022](https://insights.sbomify.com/CVE-2023-6022/): Cross-Site Request Forgery (CSRF) in prefecthq/prefect (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3514 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3514 exists.

Affected packages and fixed versions:
- prefect (PyPI): affected all versions; fixed in 3.6.22
- prefect (PyPI): affected all versions; fixed in 3.6.22.dev7
- prefect (PyPI): affected all versions; fixed in 3.6.22.dev7

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-3514/ (Markdown: https://insights.sbomify.com/CVE-2026-3514/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3514
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3514
- OSV: https://osv.dev/vulnerability/CVE-2026-3514

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3514/
Summaries are generated and may contain mistakes; the official description above is the record.