PYSEC-2026-2045

Vulnerability from pysec - Published: 2026-07-07 14:34 - Updated: 2026-07-07 17:25
VLAI
Details

On Python < 3.11 on Windows, os.path.isabs() does not catch UNC paths like //server/share. Werkzeug's safe_join() relies on this check, and so can produce a path that is not safe, potentially allowing unintended access to data. Applications using Python >= 3.11, or not using Windows, are not vulnerable.

Severity
6.3 (Medium)
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Impacted products
Name purl
werkzeug pkg:pypi/werkzeug
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "werkzeug",
        "purl": "pkg:pypi/werkzeug"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.0.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.1",
        "0.10",
        "0.10.1",
        "0.10.2",
        "0.10.3",
        "0.10.4",
        "0.11",
        "0.11.1",
        "0.11.10",
        "0.11.11",
        "0.11.12",
        "0.11.13",
        "0.11.14",
        "0.11.15",
        "0.11.2",
        "0.11.3",
        "0.11.4",
        "0.11.5",
        "0.11.6",
        "0.11.7",
        "0.11.8",
        "0.11.9",
        "0.12",
        "0.12.1",
        "0.12.2",
        "0.13",
        "0.14",
        "0.14.1",
        "0.15.0",
        "0.15.1",
        "0.15.2",
        "0.15.3",
        "0.15.4",
        "0.15.5",
        "0.15.6",
        "0.16.0",
        "0.16.1",
        "0.2",
        "0.3",
        "0.3.1",
        "0.4",
        "0.4.1",
        "0.5",
        "0.5.1",
        "0.6",
        "0.6.1",
        "0.6.2",
        "0.7",
        "0.7.1",
        "0.7.2",
        "0.8",
        "0.8.1",
        "0.8.2",
        "0.8.3",
        "0.9",
        "0.9.1",
        "0.9.2",
        "0.9.3",
        "0.9.4",
        "0.9.5",
        "0.9.6",
        "1.0.0",
        "1.0.0rc1",
        "1.0.1",
        "2.0.0",
        "2.0.0rc1",
        "2.0.0rc2",
        "2.0.0rc3",
        "2.0.0rc4",
        "2.0.0rc5",
        "2.0.1",
        "2.0.2",
        "2.0.3",
        "2.1.0",
        "2.1.1",
        "2.1.2",
        "2.2.0",
        "2.2.0a1",
        "2.2.1",
        "2.2.2",
        "2.2.3",
        "2.3.0",
        "2.3.1",
        "2.3.2",
        "2.3.3",
        "2.3.4",
        "2.3.5",
        "2.3.6",
        "2.3.7",
        "2.3.8",
        "3.0.0",
        "3.0.1",
        "3.0.2",
        "3.0.3",
        "3.0.4",
        "3.0.5"
      ]
    }
  ],
  "aliases": [
    "CVE-2024-49766",
    "GHSA-f9vj-2wh5-fj8j"
  ],
  "details": "On Python \u003c 3.11 on Windows, `os.path.isabs()` does not catch UNC paths like `//server/share`. Werkzeug\u0027s `safe_join()` relies on this check, and so can produce a path that is not safe, potentially allowing unintended access to data. Applications using Python \u003e= 3.11, or not using Windows, are not vulnerable.",
  "id": "PYSEC-2026-2045",
  "modified": "2026-07-07T17:25:51.076529Z",
  "published": "2026-07-07T14:34:43.390514Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/pallets/werkzeug/security/advisories/GHSA-f9vj-2wh5-fj8j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-49766"
    },
    {
      "type": "FIX",
      "url": "https://github.com/pallets/werkzeug/commit/2767bcb10a7dd1c297d812cc5e6d11a474c1f092"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/pallets/werkzeug"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pallets/werkzeug/releases/tag/3.0.6"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20250131-0005"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/werkzeug"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-f9vj-2wh5-fj8j"
    }
  ],
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Werkzeug safe_join not safe on Windows"
}



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