PYSEC-2026-1383

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Import Source
https://github.com/pypa/advisory-database/blob/main/vulns/flask-cors/PYSEC-2026-1383.yaml
JSON Data
https://api.test.osv.dev/v1/vulns/PYSEC-2026-1383
Aliases
Published
2026-07-07T14:34:54.132548Z
Modified
2026-07-07T17:47:39.631613331Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N CVSS Calculator
Summary
Flask-CORS vulnerable to Improper Handling of Case Sensitivity
Details

corydolphin/flask-cors version 5.0.1 contains a vulnerability where the request path matching is case-insensitive due to the use of the try_match function, which is originally intended for matching hosts. This results in a mismatch because paths in URLs are case-sensitive, but the regex matching treats them as case-insensitive. This misconfiguration can lead to significant security vulnerabilities, allowing unauthorized origins to access paths meant to be restricted, resulting in data exposure and potential data leaks.

References

Affected packages

PyPI / flask-cors

Package

Name
flask-cors
View open source insights on deps.dev
Purl
pkg:pypi/flask-cors

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.0.0

Affected versions

0.*
0.0.0.dev3
0.0.0.dev4
1.*
1.0
1.1
1.1.1
1.1.2
1.1.3
1.2.0
1.2.1
1.3.0
1.3.1
1.4.0
1.5.0
1.6.0
1.6.1
1.7.0
1.7.1
1.7.2
1.7.3
1.7.4
1.8.0
1.8.1
1.9.0
1.10.0
1.10.1
1.10.2
1.10.3
2.*
2.0.0rc1
2.0.0
2.0.1
2.1.0
2.1.1
2.1.2
2.1.3
3.*
3.0.0
3.0.1
3.0.2
3.0.3
3.0.4
3.0.6
3.0.7
3.0.8
3.0.9
3.0.10
4.*
4.0.0a0
4.0.0
4.0.1
4.0.2
5.*
5.0.0
5.0.1

Database specific

source 
"https://github.com/pypa/advisory-database/blob/main/vulns/flask-cors/PYSEC-2026-1383.yaml"