How severe is CVE-2026-34531?

CVE-2026-34531 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability none.

Is CVE-2026-34531 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34531?

CVE-2026-34531 affects Miguelgrinberg Flask-httpauth. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-34531?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-34531 have an EU (EUVD) identifier?

Yes. CVE-2026-34531 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18056.

When was CVE-2026-34531 published?

CVE-2026-34531 was published on 2026-04-01 and last updated on 2026-06-17.

CVE-2026-34531

CVE-2026-34531 is a medium-severity vulnerability in Miguelgrinberg Flask-httpauth with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18056
Weakness: CWE-287
Affected product: Miguelgrinberg Flask-httpauth
Published: 2026-04-01
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2026-34531?: 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.
How severe is CVE-2026-34531?: CVE-2026-34531 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability none.
Is CVE-2026-34531 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34531?: CVE-2026-34531 affects Miguelgrinberg Flask-httpauth. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-34531?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-34531 have an EU (EUVD) identifier?: Yes. CVE-2026-34531 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18056.
When was CVE-2026-34531 published?: CVE-2026-34531 was published on 2026-04-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:miguelgrinberg:flask-httpauth:*:*:*:*:*:python:*:*

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