Vulnerability from bitnami_vulndb
Published
2026-06-05 13:04
Modified
2026-08-19 09:09
Summary
Potential DoS via quadratic complexity in unicodedata.normalize()
Details

unicodedata.normalize() can take excessive CPU time when processing specially crafted Unicode input containing long runs of combining characters with alternating Canonical Combining Class values. This affects all normalization forms.

To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "python",
        "purl": "pkg:bitnami/python"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.10.21"
            },
            {
              "introduced": "3.11.0"
            },
            {
              "fixed": "3.11.16"
            },
            {
              "introduced": "3.12.0"
            },
            {
              "fixed": "3.12.14"
            },
            {
              "introduced": "3.13.0"
            },
            {
              "fixed": "3.13.14"
            },
            {
              "introduced": "3.14.0"
            },
            {
              "fixed": "3.14.6"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "type": "CVSS_V4"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-3276"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:python:python:*:*:*:*:*:*:*:*"
    ],
    "severity": "Medium"
  },
  "details": "unicodedata.normalize() can take excessive CPU time when processing\nspecially crafted Unicode input containing long runs of combining characters\nwith alternating Canonical Combining Class values.\nThis affects all normalization forms.",
  "id": "BIT-python-2026-3276",
  "modified": "2026-08-19T09:09:14.600Z",
  "published": "2026-06-05T13:04:10.450Z",
  "references": [
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/06/03/15"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/commit/6b505d1f41f8f3ea0fe5a4786d3a8fff1875cfc0"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/commit/991224b1e8311c85f198f6dd8208bf8cff7fc26f"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/commit/ba785b88add96acbf403d65cb157fb2743a33a32"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/commit/c5512bd7c1dc28055660565275012766941d3066"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/issues/149079"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/pull/149080"
    },
    {
      "type": "WEB",
      "url": "https://mail.python.org/archives/list/security-announce@python.org/thread/PP5HB4K7727OBBM76KA2ILID76K3OZGZ/"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-3276"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/commit/90748760d38ca3ac5fc6788a69becab905c95598"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/commit/d3ab945af25b28dfe13ac6cb40c124a01b33ce1f"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/commit/db744c0776c1d5dd11aaa70eff2a6993c408bacc"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/commit/e322a1857084d521f79f45181b776f62e6acfc2c"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Potential DoS via quadratic complexity in unicodedata.normalize()"
}



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