Medium severity5.3OSV Advisory· Published Jan 8, 2026· Updated Jun 17, 2026
CVE-2026-21860
CVE-2026-21860
Description
Werkzeug is a comprehensive WSGI web application library. Prior to version 3.1.5, Werkzeug's safe_join function allows path segments with Windows device names that have file extensions or trailing spaces. On Windows, there are special device names such as CON, AUX, etc that are implicitly present and readable in every directory. Windows still accepts them with any file extension, such as CON.txt, or trailing spaces such as CON. This issue has been patched in version 3.1.5.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
WerkzeugPyPI | < 3.1.5 | 3.1.5 |
Affected products
24- osv-coords22 versionspkg:apk/chainguard/airflow-2pkg:apk/chainguard/airflow-3pkg:apk/chainguard/airflow-core-2pkg:apk/chainguard/py3.10-ambassadorpkg:apk/chainguard/py3.11-ambassadorpkg:apk/chainguard/py3.11-azure-functions-workerpkg:apk/chainguard/py3.12-ambassadorpkg:apk/chainguard/py3.12-azure-functions-workerpkg:apk/chainguard/py3.13-ambassadorpkg:apk/chainguard/py3.13-azure-functions-workerpkg:apk/chainguard/superset-4.1pkg:apk/chainguard/superset-5.0pkg:apk/chainguard/tensorflow-cpu-jupyterpkg:apk/wolfi/airflow-3pkg:apk/wolfi/py3.10-ambassadorpkg:apk/wolfi/py3.11-ambassadorpkg:apk/wolfi/py3.12-ambassadorpkg:apk/wolfi/py3.13-ambassadorpkg:apk/wolfi/superset-4.1pkg:apk/wolfi/superset-5.0pkg:apk/wolfi/tensorflow-cpu-jupyterpkg:pypi/werkzeug
< 0+ 21 more
- (no CPE)range: < 0
- (no CPE)range: < 0
- (no CPE)range: < 0
- (no CPE)range: < 0
- (no CPE)range: < 0
- (no CPE)range: < 4.42.0-r0
- (no CPE)range: < 0
- (no CPE)range: < 4.42.0-r0
- (no CPE)range: < 0
- (no CPE)range: < 4.42.0-r0
- (no CPE)range: < 4.1.4-r7
- (no CPE)range: < 5.0.0-r12
- (no CPE)range: < 2.20.0-r8
- (no CPE)range: < 0
- (no CPE)range: < 0
- (no CPE)range: < 0
- (no CPE)range: < 0
- (no CPE)range: < 0
- (no CPE)range: < 4.1.4-r7
- (no CPE)range: < 5.0.0-r12
- (no CPE)range: < 2.20.0-r8
- (no CPE)range: < 3.1.5
Patches
Vulnerability mechanics
References
4- github.com/pallets/werkzeug/commit/7ae1d254e04a0c33e241ac1cca4783ce6c875ca3nvdPatchWEB
- github.com/advisories/GHSA-87hc-h4r5-73f7ghsaADVISORY
- github.com/pallets/werkzeug/security/advisories/GHSA-87hc-h4r5-73f7nvdVendor AdvisoryWEB
- nvd.nist.gov/vuln/detail/CVE-2026-21860ghsaADVISORY
News mentions
0No linked articles in our index yet.