CVE-2026-34531: CWE-287: Improper Authentication in miguelgrinberg Flask-HTTPAuth
CVE-2026-34531 is an improper authentication vulnerability in Flask-HTTPAuth versions prior to 4. 8. 1. When a client requests a token-protected resource without providing a token or provides an empty token, the token verification callback is invoked with an empty string. If the application has users with an empty string as their token, this could allow unauthorized authentication as those users. This issue has been fixed in version 4. 8. 1.
AI Analysis
Technical Summary
Flask-HTTPAuth, a library providing HTTP authentication for Flask routes, had a flaw in versions before 4.8.1 where requests lacking a token or with an empty token would cause the token verification callback to receive an empty string. Applications that store empty strings as valid tokens could mistakenly authenticate such requests, leading to improper authentication (CWE-287). The vulnerability has been addressed in version 4.8.1.
Potential Impact
An attacker could potentially authenticate as any user whose token is an empty string, leading to unauthorized access with limited confidentiality impact but high integrity impact. There is no indication of availability impact. The CVSS score is 6.5 (medium severity), reflecting network attack vector, high attack complexity, no privileges required, no user interaction, unchanged scope, low confidentiality impact, high integrity impact, and no availability impact.
Mitigation Recommendations
Upgrade Flask-HTTPAuth to version 4.8.1 or later where this vulnerability is patched. No other mitigations are indicated or required according to the available data.
CVE-2026-34531: CWE-287: Improper Authentication in miguelgrinberg Flask-HTTPAuth
Description
CVE-2026-34531 is an improper authentication vulnerability in Flask-HTTPAuth versions prior to 4. 8. 1. When a client requests a token-protected resource without providing a token or provides an empty token, the token verification callback is invoked with an empty string. If the application has users with an empty string as their token, this could allow unauthorized authentication as those users. This issue has been fixed in version 4. 8. 1.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Flask-HTTPAuth, a library providing HTTP authentication for Flask routes, had a flaw in versions before 4.8.1 where requests lacking a token or with an empty token would cause the token verification callback to receive an empty string. Applications that store empty strings as valid tokens could mistakenly authenticate such requests, leading to improper authentication (CWE-287). The vulnerability has been addressed in version 4.8.1.
Potential Impact
An attacker could potentially authenticate as any user whose token is an empty string, leading to unauthorized access with limited confidentiality impact but high integrity impact. There is no indication of availability impact. The CVSS score is 6.5 (medium severity), reflecting network attack vector, high attack complexity, no privileges required, no user interaction, unchanged scope, low confidentiality impact, high integrity impact, and no availability impact.
Mitigation Recommendations
Upgrade Flask-HTTPAuth to version 4.8.1 or later where this vulnerability is patched. No other mitigations are indicated or required according to the available data.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-30T16:03:31.048Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 69cd8944e6bfc5ba1dfc32e5
Added to database: 4/1/2026, 9:08:20 PM
Last enriched: 4/10/2026, 12:02:20 AM
Last updated: 5/17/2026, 3:52:33 AM
Views: 71
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.