BREW-PYDANTIC-CVE-2021-29510 (GHSA-5JQP-QGF6-3PVH)

Vulnerability from osv_homebrew – Published: 2026-08-13 17:29 – Updated: 2026-09-10 00:59 – Source website
VLAI
Summary
Use of "infinity" as an input to datetime and date fields causes infinite loop in pydantic
Details

Impact

Passing either 'infinity', 'inf' or float('inf') (or their negatives) to datetime or date fields causes validation to run forever with 100% CPU usage (on one CPU). Patches

Pydantic is be patched with fixes available in the following versions:

v1.8.2
v1.7.4
v1.6.2

All these versions are available on pypi, and will be available on conda-forge soon.

See the changelog for details. Workarounds

If you absolutely can't upgrade, you can work around this risk using a validator to catch these values, brief demo:

from datetime import date from pydantic import BaseModel, validator

class DemoModel(BaseModel): date_of_birth: date

@validator('date_of_birth', pre=True)
def skip_infinite_values(cls, v):
    try:
        seconds = float(v)
    except (ValueError, TypeError):
        return v
    else:
        if seconds == float('inf'):
            return date.max
        elif seconds == float('-inf'):
            return date.min
        else:
            return seconds

Note: this is not an ideal solution (in particular you'll need a slightly different function for datetimes), instead of a hack like this you should upgrade pydantic.

If you are not using v1.8.x, v1.7.x or v1.6.x and are unable to upgrade to a fixed version of pydantic, please create an issue requesting a back-port, and we will endeavour to release a patch for earlier versions of pydantic. References

This was fixed in commit 7e83fdd.

Severity
3.3 (Low)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
5.3 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "upstream_fixed_in": "1.8.2"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "pydantic",
        "purl": "pkg:brew/pydantic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.13.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/pydantic@2.13.5",
        "name": "pydantic",
        "strategy": "registry",
        "subject_version": "2.13.5"
      },
      {
        "ecosystem": "Debian",
        "key": "Debian/pydantic",
        "name": "pydantic",
        "strategy": "distro"
      },
      {
        "ecosystem": "PyPI",
        "key": "upstream:pkg:pypi/pydantic@2.13.5",
        "name": "pydantic",
        "strategy": "distro",
        "subject_version": "2.13.5"
      },
      {
        "ecosystem": "Ubuntu",
        "key": "Ubuntu/pydantic",
        "name": "pydantic",
        "strategy": "distro"
      }
    ]
  },
  "details": "Impact\n\nPassing either \u0027infinity\u0027, \u0027inf\u0027 or float(\u0027inf\u0027) (or their negatives) to datetime or date fields causes validation to run forever with 100% CPU usage (on one CPU).\nPatches\n\nPydantic is be patched with fixes available in the following versions:\n\n    v1.8.2\n    v1.7.4\n    v1.6.2\n\nAll these versions are available on pypi, and will be available on conda-forge soon.\n\nSee the changelog for details.\nWorkarounds\n\nIf you absolutely can\u0027t upgrade, you can work around this risk using a validator to catch these values, brief demo:\n\nfrom datetime import date\nfrom pydantic import BaseModel, validator\n\nclass DemoModel(BaseModel):\n    date_of_birth: date\n\n    @validator(\u0027date_of_birth\u0027, pre=True)\n    def skip_infinite_values(cls, v):\n        try:\n            seconds = float(v)\n        except (ValueError, TypeError):\n            return v\n        else:\n            if seconds == float(\u0027inf\u0027):\n                return date.max\n            elif seconds == float(\u0027-inf\u0027):\n                return date.min\n            else:\n                return seconds\n\nNote: this is not an ideal solution (in particular you\u0027ll need a slightly different function for datetimes), instead of a hack like this you should upgrade pydantic.\n\nIf you are not using v1.8.x, v1.7.x or v1.6.x and are unable to upgrade to a fixed version of pydantic, please create an issue requesting a back-port, and we will endeavour to release a patch for earlier versions of pydantic.\nReferences\n\nThis was fixed in commit 7e83fdd.",
  "id": "BREW-pydantic-CVE-2021-29510",
  "modified": "2026-09-10T00:59:04Z",
  "published": "2026-08-13T17:29:36Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/samuelcolvin/pydantic/security/advisories/GHSA-5jqp-qgf6-3pvh"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-29510"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pydantic/pydantic/commit/1c24f1d74ba95ea985b50bdc001ce96c813229aa"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pydantic/pydantic/commit/80e0dd3f752bef145dce12f160d262bb40ec8d47"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pydantic/pydantic/commit/bdde15b7b947c94ca00fd6eb92da8db390a13520"
    },
    {
      "type": "WEB",
      "url": "https://github.com/samuelcolvin/pydantic/commit/7e83fdd2563ffac081db7ecdf1affa65ef38c468"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/pydantic/pydantic"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/pydantic/PYSEC-2021-47.yaml"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/S2HT266L6Q7H6ICP7DFGXOGBJHNNKMKB"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UEFWM7DYKD2ZHE7R5YT5EQWJPV4ZKYRB"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UMKAJX4O6IGBBCE32CO2G7PZQCCQSBLV"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Use of \"infinity\" as an input to datetime and date fields causes infinite loop in pydantic",
  "upstream": [
    "GHSA-5jqp-qgf6-3pvh",
    "CVE-2021-29510",
    "PYSEC-2021-47"
  ]
}



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