Description
Werkzeug is a comprehensive WSGI web application library. Prior to version 3.1.4, 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. This issue has been patched in version 3.1.4.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| pallets | werkzeug | < 3.1.4 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python-openapi-core | 0.22.0-1.1 | openSUSE-SU-2025:15848-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | py3-werkzeug | 3.1.4-r0 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | werkzeug | < 3.1.4 | 3.1.4 | GHSA-hgf8-39gv-g3f2 |
Advisories 2
- WID-SEC-2026-2933 Splunk SOAR: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 2, 2026
- openSUSE-SU-2025:15848-1 python311-openapi-core-0.22.0-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026