CVE-2026-34531
Flask-HTTPAuth invokes token verification callback when missing or empty token was given by client
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
11th
Flask-HTTPAuth provides Basic, Digest and Token HTTP authentication for Flask routes. Prior to version 4.8.1, in a situation where the client makes a request to a token protected resource without passing a token, or passing an empty token, Flask-HTTPAuth would invoke the application's token verification callback function with the token argument set to an empty string. If the application had any users in its database with an empty string set as their token, then it could potentially authenticate the client request against any of those users. This issue has been patched in version 4.8.1.
| CWE | CWE-287 |
| Vendor | miguelgrinberg |
| Product | flask-httpauth |
| Published | Apr 1, 2026 |
| Last Updated | Apr 2, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
High
Availability
None
Affected Versions
miguelgrinberg / Flask-HTTPAuth
< 4.8.1