Read the docs
TI-2026-26780 Aliases CVE-2026-34531GHSA-p44q-vqpr-4xmg

Flask-HTTPAuth invokes token verification callback when missing or empty token was given by client

Priority LOW 36CWE-287Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
Low · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-287.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00337 27th percentileScored 2026-11-07
Fix Fixed Flask-HTTPAuth (miguelgrinberg): 4.8.1Flask-HTTPAuth (PyPI): 4.8.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
miguelgrinbergFlask-HTTPAuthbefore 4.8.14.8.1Patch availableCNA
—Flask-HTTPAuth (PyPI)before 4.8.14.8.1Patch availableGHSA-p44q-vqpr-4xmg
  • Flask-HTTPAuth Vendormiguelgrinberg Affected before 4.8.1 Fixed in 4.8.1 Patch available CNA
  • Flask-HTTPAuth (PyPI) Vendor— Affected before 4.8.1 Fixed in 4.8.1 Patch available GHSA-p44q-vqpr-4xmg

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:miguelgrinberg:flask-httpauth:*:*:*:*:*:python:*:*before 4.8.1Vulnerablemiguelgrinberg
  • cpe:2.3:a:miguelgrinberg:flask-httpauth:*:*:*:*:*:python:*:* Versions before 4.8.1 Vulnerable ·miguelgrinberg

Remediation

  • Fix · CNA Flask-HTTPAuth (miguelgrinberg) Fixed in 4.8.1
  • Fix · GHSA-p44q-vqpr-4xmg Flask-HTTPAuth (PyPI) Fixed in 4.8.1 Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34531
  2. 2026-10-03 Alias added: GHSA-p44q-vqpr-4xmg

References

Patch 1

Advisory 2

Other 3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences