PYSEC-2026-1385
Flask-CORS allows for inconsistent CORS matching
At a glance
- Published
- Updated
- CVE
- CVE-2024-6844
- Aliases
- GHSA-8vgw-p6qm-5gr7
- CVSS_V3
- CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Description
A vulnerability in corydolphin/flask-cors version 5.0.1 allows for inconsistent CORS matching due to the handling of the '+' character in URL paths. The request.path is passed through the unquote_plus function, which converts the '+' character to a space ' '. This behavior leads to incorrect path normalization, causing potential mismatches in CORS configuration. As a result, endpoints may not be matched correctly to their CORS settings, leading to unexpected CORS policy application. This can cause unauthorized cross-origin access or block valid requests, creating security vulnerabilities and usability issues.
Affected packages
| Package | Versions |
|---|---|
| PyPI · flask-cors | introduced 0, fixed 6.0.0 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2024-6844 ADVISORY
- https://github.com/corydolphin/flask-cors/commit/35d875319621bd129a38b2b823abf4a2f6cda536 WEB
- https://github.com/corydolphin/flask-cors PACKAGE
- https://github.com/corydolphin/flask-cors/blob/main/flask_cors/extension.py#L193 WEB
- https://huntr.com/bounties/731a6cd4-d05f-4fe6-8f5b-fe088d7b34e0 WEB
- https://lists.debian.org/debian-lts-announce/2025/05/msg00049.html WEB
- https://pypi.org/project/flask-cors PACKAGE
- https://github.com/advisories/GHSA-8vgw-p6qm-5gr7 ADVISORY
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — PyPA Advisory Database |