Flask-AppBuilder Observable Response Discrepancy
Impact
User enumeration in database authentication in Flask-AppBuilder <= 4.5.3 and werkzeug >= 3.0.0. Allows for a non authenticated user to enumerate existing usernames by timing the response time from the server when brute forcing requests to login.
Patches
Upgrade to flask-appbuilder>=4.5.3
Workarounds
Downgrade werkzeug to <3.0.0
References
Are there any links users can visit to find out more?
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | flask-appbuilder | < 4.5.3 | 4.5.3 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N- Weakness (CWE)
CWE-204- Platform
- Python (PyPI)
- Package
flask-appbuilder- Disclosed
- 03.03.2025
- Updated
- 11.10.2026 15:17
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2025-15 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-p8q5-cvwx-wvwp - CC BY 4.0
Vulnerability history: flask-appbuilder
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 14
- First → latest
- 05.2021 09.2025
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- High 2
- Medium 9
- Low 2
Disclosures per year
- 2021: 3
- 2022: 3
- 2023: 2
- 2024: 3
- 2025: 3
- 2026: 0
-
Flask-AppBuilder Observable Response Discrepancy this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.