Werkzeug safe_join not safe on Windows
On Python < 3.11 on Windows, os.path.isabs() does not catch UNC paths like //server/share. Werkzeug's safe_join() relies on this check, and so can produce a path that is not safe, potentially allowing unintended access to data. Applications using Python >= 3.11, or not using Windows, are not vulnerable.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | werkzeug | < 3.0.6 | 3.0.6 |
References
- https://github.com/pallets/werkzeug/security/advisories/GHSA-f9vj-2wh5-fj8j
- https://nvd.nist.gov/vuln/detail/CVE-2024-49766
- https://github.com/pallets/werkzeug/commit/2767bcb10a7dd1c297d812cc5e6d11a474c1f092
- https://github.com/pallets/werkzeug
- https://github.com/pallets/werkzeug/releases/tag/3.0.6
- https://security.netapp.com/advisory/ntap-20250131-0005
- https://pypi.org/project/werkzeug
- https://github.com/advisories/GHSA-f9vj-2wh5-fj8j
- CVSS vector
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N- Weakness (CWE)
CWE-22- Platform
- Python (PyPI)
- Package
werkzeug- Disclosed
- 25.10.2024
- Updated
- 11.10.2026 15:17
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-2045 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-f9vj-2wh5-fj8j - CC BY 4.0
Vulnerability history: werkzeug
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
- 15
- First → latest
- 10.2017 10.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 4
- Medium 9
- Low 1
- Unrated 1
Disclosures per year
- 2017: 1
- 2018: 0
- 2019: 1
- 2020: 1
- 2021: 0
- 2022: 2
- 2023: 3
- 2024: 3
- 2025: 1
- 2026: 3
-
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