CVE catalog
CVE-2025-66221
python-werkzeug: CVE-2025-66221
- Severity
- Medium · CVSS 6.3
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.51% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | python-werkzeug | sid | 3.1.9-1 | not affected |
| Debian | python-werkzeug | forky | 3.1.9-1 | not affected |
| Debian | python-werkzeug | trixie | 3.1.3-2 | not affected |
| Debian | python-werkzeug | bookworm | 2.2.2-3+deb12u1 | not affected |
| PyPI | werkzeug | Not reported | 3.1.4 | fixed |
| Cpe | werkzeug | Not reported | 3.1.4 | fixed |
| Alpine | py3-werkzeug | 3.24 | 3.1.4-r0 | fixed |
| Opensuse | python-openapi-core | tumbleweed | 0.22.0-1.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | python-werkzeug | source | sid | Not affected | unimportant | Not reported | Not reported |
| Debian | python-werkzeug | source | forky | Not affected | unimportant | Not reported | Not reported |
| Debian | python-werkzeug | source | trixie | Not affected | unimportant | Not reported | Not reported |
| Debian | python-werkzeug | source | bookworm | Not affected | unimportant | Not reported | Not reported |
| PyPI | werkzeug | PyPI | Not reported | 3.1.4 | Not reported | GHSA-HGF8-39GV-G3F2 | Not reported |
| Cpe | werkzeug | cpe | Not reported | 3.1.4 | Not reported | NVD-CVE-2025-66221 | Not reported |
| Alpine | py3-werkzeug | apk | 3.24 | 3.1.4-r0 | Not reported | ALPINE-CVE-2025-66221 | Not reported |
| Opensuse | python-openapi-core | rpm | tumbleweed | 0.22.0-1.1 | Not reported | OPENSUSE-SU-2025:15848-1 | Not reported |
OpenFactory catalog packages
[openSUSE Tumbleweed]
- [python313-openapi-core]Unknown
Source package: [python-openapi-core]
Details (1)
0.23.1+git55-1.1· noarch · tumbleweedUnknown · Fixed:
0.22.0-1.1Version impact unknown
dsa · python-openapi-core · opensuse · tumbleweed
- [python314-openapi-core]Unknown
Source package: [python-openapi-core]
Details (1)
0.23.1+git55-1.1· noarch · tumbleweedUnknown · Fixed:
0.22.0-1.1Version impact unknown
dsa · python-openapi-core · opensuse · tumbleweed
[Debian 12 (Bookworm)]
- [python3-werkzeug]Not affected
Source package: [python-werkzeug]
Details (2)
2.2.2-3+deb12u1· all · bookwormNot affected
dsa · python-werkzeug · debian · bookworm
2.2.2-3+deb12u1· all · bookwormNot affected
dsa · python-werkzeug · debian · bookworm
- [python-werkzeug-doc]Not affected
Source package: [python-werkzeug]
Details (2)
2.2.2-3+deb12u1· all · bookwormNot affected
dsa · python-werkzeug · debian · bookworm
2.2.2-3+deb12u1· all · bookwormNot affected
dsa · python-werkzeug · debian · bookworm
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2025_15848-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2025-66221]
- [https://osv.dev/vulnerability/ALPINE-CVE-2025-66221]
- [https://osv.dev/vulnerability/GHSA-hgf8-39gv-g3f2]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2025-66221]
- [https://osv.dev/vulnerability/openSUSE-SU-2025:15848-1]
- [https://security-tracker.debian.org/tracker/CVE-2025-66221]
- [https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-66221.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2933.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]