Python/werkzeug/3.1.0
The comprehensive WSGI web application library.
https://pypi.org/project/werkzeug
BSD
2 Security Vulnerabilities
Werkzeug safe_join() allows Windows special device names
Published date: 2026-02-19T20:32:45Z
CVE: CVE-2026-27199
Links:
- https://github.com/pallets/werkzeug/security/advisories/GHSA-29vq-49wr-vm6x
- https://github.com/pallets/werkzeug/commit/f407712fdc60a09c2b3f4fe7db557703e5d9338d
- https://github.com/pallets/werkzeug/releases/tag/3.1.6
- https://github.com/advisories/GHSA-29vq-49wr-vm6x
- https://nvd.nist.gov/vuln/detail/CVE-2026-27199
Werkzeug's safe_join function allows Windows device names as filenames if when preceded by other path segments.
This was previously reported as https://github.com/pallets/werkzeug/security/advisories/GHSA-hgf8-39gv-g3f2, but the added filtering failed to account for the fact that safe_join accepts paths with multiple segments, such as example/NUL.
send_from_directory uses safe_join to safely serve files at user-specified paths under a directory. If the application is running on Windows, and the requested path ends with a special device name, the file will be opened successfully, but reading will hang indefinitely.
Affected versions: ["3.1.5", "3.1.4", "3.1.3", "3.1.2", "3.1.1", "3.1.0", "3.0.6", "3.0.5", "3.0.4", "3.0.3", "3.0.2", "3.0.1", "3.0.0", "2.3.8", "2.3.7", "2.3.6", "2.3.5", "2.3.4", "2.3.3", "2.3.2", "2.3.1", "2.3.0", "2.2.3", "2.2.2", "2.2.1", "2.2.0", "2.2.0a1", "2.1.2", "2.1.1", "2.1.0", "2.0.3", "2.0.2", "2.0.1", "2.0.0", "2.0.0rc5", "2.0.0rc4", "2.0.0rc3", "2.0.0rc2", "2.0.0rc1", "1.0.1", "1.0.0", "1.0.0rc1", "0.16.1", "0.16.0", "0.15.6", "0.15.5", "0.15.4", "0.15.3", "0.15.2", "0.15.1", "0.15.0", "0.14.1", "0.14", "0.13", "0.12.2", "0.12.1", "0.12", "0.11.15", "0.11.14", "0.11.13", "0.11.12", "0.11.11", "0.11.10", "0.11.9", "0.11.8", "0.11.7", "0.11.6", "0.11.5", "0.11.4", "0.11.3", "0.11.2", "0.11.1", "0.11", "0.10.4", "0.10.3", "0.10.2", "0.10.1", "0.10", "0.9.6", "0.9.5", "0.9.4", "0.9.3", "0.9.2", "0.9.1", "0.9", "0.8.3", "0.8.2", "0.8.1", "0.8", "0.7.2", "0.7.1", "0.7", "0.6.2", "0.6.1", "0.6", "0.5.1", "0.5", "0.4.1", "0.4", "0.3.1", "0.3", "0.2", "0.1"]
Secure versions: [3.1.6, 3.1.7, 3.1.8]
Recommendation: Update to version 3.1.8.
Werkzeug safe_join() allows Windows special device names
Published date: 2025-12-02T00:27:38Z
CVE: CVE-2025-66221
Links:
- https://github.com/pallets/werkzeug/security/advisories/GHSA-hgf8-39gv-g3f2
- https://nvd.nist.gov/vuln/detail/CVE-2025-66221
- https://github.com/pallets/werkzeug/commit/4b833376a45c323a189cd11d2362bcffdb1c0c13
- https://github.com/pallets/werkzeug/releases/tag/3.1.4
- https://github.com/advisories/GHSA-hgf8-39gv-g3f2
Werkzeug's safe_join function allows path segments with Windows device names. On Windows, there are special device names such as CON, AUX, etc that are implicitly present and readable in every directory. send_from_directory uses safe_join to safely serve files at user-specified paths under a directory. If the application is running on Windows, and the requested path ends with a special device name, the file will be opened successfully, but reading will hang indefinitely.
Affected versions: ["3.1.3", "3.1.2", "3.1.1", "3.1.0", "3.0.6", "3.0.5", "3.0.4", "3.0.3", "3.0.2", "3.0.1", "3.0.0", "2.3.8", "2.3.7", "2.3.6", "2.3.5", "2.3.4", "2.3.3", "2.3.2", "2.3.1", "2.3.0", "2.2.3", "2.2.2", "2.2.1", "2.2.0", "2.2.0a1", "2.1.2", "2.1.1", "2.1.0", "2.0.3", "2.0.2", "2.0.1", "2.0.0", "2.0.0rc5", "2.0.0rc4", "2.0.0rc3", "2.0.0rc2", "2.0.0rc1", "1.0.1", "1.0.0", "1.0.0rc1", "0.16.1", "0.16.0", "0.15.6", "0.15.5", "0.15.4", "0.15.3", "0.15.2", "0.15.1", "0.15.0", "0.14.1", "0.14", "0.13", "0.12.2", "0.12.1", "0.12", "0.11.15", "0.11.14", "0.11.13", "0.11.12", "0.11.11", "0.11.10", "0.11.9", "0.11.8", "0.11.7", "0.11.6", "0.11.5", "0.11.4", "0.11.3", "0.11.2", "0.11.1", "0.11", "0.10.4", "0.10.3", "0.10.2", "0.10.1", "0.10", "0.9.6", "0.9.5", "0.9.4", "0.9.3", "0.9.2", "0.9.1", "0.9", "0.8.3", "0.8.2", "0.8.1", "0.8", "0.7.2", "0.7.1", "0.7", "0.6.2", "0.6.1", "0.6", "0.5.1", "0.5", "0.4.1", "0.4", "0.3.1", "0.3", "0.2", "0.1"]
Secure versions: [3.1.6, 3.1.7, 3.1.8]
Recommendation: Update to version 3.1.8.
106 Other Versions
| Version | License | Security | Released | |
|---|---|---|---|---|
| 3.1.8 | UNKNOWN | |||
| 3.1.7 | UNKNOWN | |||
| 3.1.6 | UNKNOWN | |||
| 3.1.5 | UNKNOWN | 1 | ||
| 3.1.4 | UNKNOWN | 1 | ||
| 3.1.3 | BSD | 2 | 1970-01-01 - 00:00 | over 56 years |
| 3.1.2 | BSD | 2 | 1970-01-01 - 00:00 | over 56 years |
| 3.1.1 | BSD | 2 | 1970-01-01 - 00:00 | over 56 years |
| 3.1.0 | BSD | 2 | 1970-01-01 - 00:00 | over 56 years |
| 3.0.6 | BSD | 2 | 1970-01-01 - 00:00 | over 56 years |
| 3.0.5 | BSD | 3 | 1970-01-01 - 00:00 | over 56 years |
| 3.0.4 | BSD | 3 | 1970-01-01 - 00:00 | over 56 years |
| 3.0.3 | BSD | 3 | 1970-01-01 - 00:00 | over 56 years |
| 3.0.2 | BSD | 3 | 1970-01-01 - 00:00 | over 56 years |
| 3.0.1 | BSD | 3 | 1970-01-01 - 00:00 | over 56 years |
| 3.0.0 | BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.3.8 | BSD | 3 | 1970-01-01 - 00:00 | over 56 years |
| 2.3.7 | BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.3.6 | BSD-3-Clause AND BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.3.5 | BSD-3-Clause AND BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.3.4 | BSD-3-Clause AND BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.3.3 | BSD-3-Clause AND BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.3.2 | BSD-3-Clause AND BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.3.1 | BSD-3-Clause AND BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.3.0 | BSD-3-Clause AND BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.2.3 | BSD-3-Clause AND BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.2.2 | BSD-3-Clause AND BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.2.1 | BSD-3-Clause AND BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.2.0 | BSD-3-Clause AND BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.2.0a1 | BSD-3-Clause AND BSD | 4 | 1970-01-01 - 00:00 | over 56 years |
| 2.1.2 | BSD-3-Clause AND BSD | 4 | 2022-04-28 - 17:39 | about 4 years |
| 2.1.1 | BSD-3-Clause AND BSD | 4 | 2022-04-01 - 16:01 | about 4 years |
| 2.1.0 | BSD-3-Clause AND BSD | 4 | 2022-03-28 - 17:55 | about 4 years |
| 2.0.3 | BSD-3-Clause AND BSD | 4 | 2022-02-07 - 21:04 | about 4 years |
| 2.0.2 | BSD-3-Clause AND BSD | 4 | 2021-10-06 - 00:27 | over 4 years |
| 2.0.1 | BSD-3-Clause AND BSD | 4 | 2021-05-17 - 23:16 | almost 5 years |
| 2.0.0 | BSD-3-Clause AND BSD | 4 | 2021-05-11 - 20:26 | almost 5 years |
| 2.0.0rc5 | BSD-3-Clause AND BSD | 4 | 2021-05-03 - 14:16 | almost 5 years |
| 2.0.0rc4 | BSD-3-Clause AND BSD | 4 | 2021-04-16 - 15:35 | about 5 years |
| 2.0.0rc3 | BSD-3-Clause AND BSD | 4 | 2021-03-17 - 20:42 | about 5 years |
| 2.0.0rc2 | BSD-3-Clause AND BSD | 4 | 2021-03-03 - 20:45 | about 5 years |
| 2.0.0rc1 | BSD-3-Clause AND BSD | 4 | 2021-02-08 - 15:20 | about 5 years |
| 1.0.1 | BSD-3-Clause AND BSD | 4 | 2020-03-31 - 18:03 | about 6 years |
| 1.0.0 | BSD-3-Clause AND BSD | 4 | 2020-02-06 - 20:25 | about 6 years |
| 1.0.0rc1 | BSD-3-Clause AND BSD | 4 | 2020-01-31 - 16:58 | about 6 years |
| 0.16.1 | BSD-3-Clause AND BSD | 4 | 2020-01-27 - 04:13 | over 6 years |
| 0.16.0 | BSD-3-Clause AND BSD | 4 | 2019-09-19 - 14:39 | over 6 years |
| 0.15.6 | BSD-3-Clause AND BSD | 4 | 2019-09-04 - 20:09 | over 6 years |
| 0.15.5 | BSD-3-Clause AND BSD | 4 | 2019-07-17 - 15:31 | almost 7 years |
| 0.15.4 | BSD-3-Clause AND BSD | 5 | 2019-05-15 - 01:49 | almost 7 years |