id: PYSEC-2026-1383
published: "2026-07-07T14:34:54.132548Z"
modified: "2026-07-07T17:24:09.393861Z"
aliases:
- CVE-2024-6866
- GHSA-43qf-4rqw-9q2g
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.
affected:
- package:
    name: flask-cors
    ecosystem: PyPI
    purl: pkg:pypi/flask-cors
  ranges:
  - type: ECOSYSTEM
    events:
    - introduced: "0"
    - fixed: 6.0.0
  versions:
  - 0.0.0.dev3
  - 0.0.0.dev4
  - "1.0"
  - "1.1"
  - 1.1.1
  - 1.1.2
  - 1.1.3
  - 1.10.0
  - 1.10.1
  - 1.10.2
  - 1.10.3
  - 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
  - 2.0.0
  - 2.0.0rc1
  - 2.0.1
  - 2.1.0
  - 2.1.1
  - 2.1.2
  - 2.1.3
  - 3.0.0
  - 3.0.1
  - 3.0.10
  - 3.0.2
  - 3.0.3
  - 3.0.4
  - 3.0.6
  - 3.0.7
  - 3.0.8
  - 3.0.9
  - 4.0.0
  - 4.0.0a0
  - 4.0.1
  - 4.0.2
  - 5.0.0
  - 5.0.1
references:
- type: ADVISORY
  url: https://nvd.nist.gov/vuln/detail/CVE-2024-6866
- type: WEB
  url: https://github.com/corydolphin/flask-cors/commit/eb39516a3c96b90d0ae5f51293972395ec3ef358
- type: PACKAGE
  url: https://github.com/corydolphin/flask-cors
- type: WEB
  url: "https://github.com/corydolphin/flask-cors/blob/4.0.1/flask_cors/extension.py#L195"
- type: WEB
  url: https://huntr.com/bounties/808c11af-faee-43a8-824b-b5ab4f62b9e6
- type: WEB
  url: https://lists.debian.org/debian-lts-announce/2025/05/msg00049.html
- type: PACKAGE
  url: https://pypi.org/project/flask-cors
- type: ADVISORY
  url: https://github.com/advisories/GHSA-43qf-4rqw-9q2g
severity:
- type: CVSS_V3
  score: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N