Description
A vulnerability in corydolphin/flask-cors version 4.0.1 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.
References (2)
Core 2
Core References
Exploit, Third Party Advisory
https://huntr.com/bounties/731a6cd4-d05f-4fe6-8f5b-fe088d7b34e0
Scores
CVSS v3
5.3
EPSS
0.0027
EPSS Percentile
18.7%
Attack Vector
NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-346
Status
published
Products (2)
flask-cors_project/flask-cors
4.0.1
pypi/flask-cors
0 - 6.0.0PyPI
Published
Mar 20, 2025
Tracked Since
Feb 18, 2026