CVE-2021-32618: The Python "Flask-Security-Too" package is used for adding security features to your Flask application

Routine

LOW 3.1MITIGATE

CVE-2021-32618 is a low-severity flaw (CVSS 3.1) affecting flask-security. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Python "Flask-Security-Too" package is used for adding security features to your Flask application. It is an is an independently maintained version of Flask-Security based on the 3.0.0 version of Flask-Security. All versions of Flask-Security-Too allow redirects after many successful views (e.g. /login) by honoring the ?next query param. There is code in FS to validate that the url specified in the next parameter is either relative OR has the

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	3.1 (Low)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	Required
EPSS exploit chance	2.8% (top 13%)
CISA exploited list	No
Weakness	CWE-601
Published	2021-05-17
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: flask-security project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-05-17 18:15 UTCPublished CVE record published
2026-06-17 03:53 UTCUpdated Record last modified

flask-security project flask-security MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy flask-security || rpm -q flask-security || flask-security --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Nuclei scan template: Python Flask-Security - Open Redirect

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-32618?

flask-security: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-32618 being exploited?

CVE-2021-32618 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-32618 affect?

CVE-2021-32618 affects flask-security. Severity is low (CVSS 3.1). The Python "Flask-Security-Too" package is used for adding security features to your Flask application. It is an is an independently maintained version of Flask-Security based on the 3.0.0 version of Flask-Security. All versions of Flask-Se

How urgent is CVE-2021-32618?

Priority 33/100. No elevated risk signals yet.

Software pages

Python vulnerabilities · Flask vulnerabilities

Related CVEs

CVE-2021-23385 MEDIUM 5.4 MITIGATE This affects all versions of package Flask-Security

References

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