Prefect SSRF Bypass via DNS Rebinding in validate_restricted_url
Low5.0CVE-2026-7724 · Published May 4, 2026 · updated Sep 10, 2026
A vulnerability has been found in PrefectHQ prefect up to 3.6.28.dev1. Affected by this vulnerability is the function validate_restricted_url of the component Webhook/Notification. The manipulation leads to time-of-check time-of-use. It is possible to initiate the attack remotely. The attack is considered to have high complexity. The exploitation appears to be difficult. The exploit has been disclosed to the public and may be used. Upgrading to version 3.6.28.dev2 addresses this issue. The identifier of the patch is 7c70ac54a5e101431d83b9f2681ec88d5e0021ed. Upgrading the affected component is advised.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| prefect PyPI | < 3.6.28.dev2 | 3.6.28.dev2 |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-362
- Also known as
- CVE-2026-7724, PYSEC-2026-2959
- nvd.nist.gov/vuln/detail/CVE-2026-7724
- github.com/PrefectHQ/prefect/pull/21591
- github.com/PrefectHQ/prefect/commit/7c70ac54a5e101431d83b9f2681ec88d5e0021ed
- gist.github.com/nedlir/fa99777e8989414585d08c3625bf044a
- github.com/PrefectHQ/prefect
- github.com/PrefectHQ/prefect/releases/tag/3.6.28.dev2
- linear.app/prefect/issue/OSS-7874/fix-dns-rebinding-toctou-bypass-in-validate-restricted-url
- vuldb.com/submit/807303
- vuldb.com/vuln/360900
- vuldb.com/vuln/360900/cti
More Prefect advisories
All Prefect| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Jun 2 | Prefect has an Authentication Middleware Bypass when URL paths are appended with 'health' or 'ready' | High7.5 | 3.6.22.dev7 |
| May 26 | Prefect has an Argument Injection issue | High8.5 | No fix yet |
| May 4 | Prefect Git Argument Injection in GitRepository Pull Steps | Low6.3 | 3.6.25.dev7 |
| May 4 | Prefect Auth Bypass via endswith() Health Check Exemption | Medium5.3 | 3.6.22 |
| May 4 | Prefect Unauthenticated Event Injection via /api/events/in WebSocket | Medium7.3 | 3.6.14 |
| Mar 202025 | Prefect CORS (Cross-Origin Resource Sharing) misconfiguration | High7.6 | 2.20.17+1 more |