PYSEC-2026-1385

Vulnerability from pysec - Published: 2026-07-07 14:34 - Updated: 2026-07-07 17:24
VLAI
Details

A vulnerability in corydolphin/flask-cors version 5.0.1 allows for inconsistent CORS matching due to the handling of the '+' character in URL paths. The request.path is passed through the unquote_plus function, which converts the '+' character to a space ' '. This behavior leads to incorrect path normalization, causing potential mismatches in CORS configuration. As a result, endpoints may not be matched correctly to their CORS settings, leading to unexpected CORS policy application. This can cause unauthorized cross-origin access or block valid requests, creating security vulnerabilities and usability issues.

Severity
5.3 (Medium)
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Impacted products
Name purl
flask-cors pkg:pypi/flask-cors
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "flask-cors",
        "purl": "pkg:pypi/flask-cors"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "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"
      ]
    }
  ],
  "aliases": [
    "CVE-2024-6844",
    "GHSA-8vgw-p6qm-5gr7"
  ],
  "details": "A vulnerability in corydolphin/flask-cors version 5.0.1 allows for inconsistent CORS matching due to the handling of the \u0027+\u0027 character in URL paths. The request.path is passed through the unquote_plus function, which converts the \u0027+\u0027 character to a space \u0027 \u0027. This behavior leads to incorrect path normalization, causing potential mismatches in CORS configuration. As a result, endpoints may not be matched correctly to their CORS settings, leading to unexpected CORS policy application. This can cause unauthorized cross-origin access or block valid requests, creating security vulnerabilities and usability issues.",
  "id": "PYSEC-2026-1385",
  "modified": "2026-07-07T17:24:09.519591Z",
  "published": "2026-07-07T14:34:54.518645Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-6844"
    },
    {
      "type": "WEB",
      "url": "https://github.com/corydolphin/flask-cors/commit/35d875319621bd129a38b2b823abf4a2f6cda536"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/corydolphin/flask-cors"
    },
    {
      "type": "WEB",
      "url": "https://github.com/corydolphin/flask-cors/blob/main/flask_cors/extension.py#L193"
    },
    {
      "type": "WEB",
      "url": "https://huntr.com/bounties/731a6cd4-d05f-4fe6-8f5b-fe088d7b34e0"
    },
    {
      "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-8vgw-p6qm-5gr7"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Flask-CORS allows for inconsistent CORS matching"
}


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