Use of "infinity" as an input to datetime and date fields causes infinite loop in pydantic
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
v1.6.2All 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 secondsNote: 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.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | pydantic | < 1.6.2, >= 1.8, < 1.8.2, >= 1.7, < 1.7.4 | 1.6.2, 1.8.2, 1.7.4 |
References
- https://github.com/samuelcolvin/pydantic/security/advisories/GHSA-5jqp-qgf6-3pvh
- https://github.com/samuelcolvin/pydantic/commit/7e83fdd2563ffac081db7ecdf1affa65ef38c468
- https://nvd.nist.gov/vuln/detail/CVE-2021-29510
- https://github.com/pydantic/pydantic/commit/1c24f1d74ba95ea985b50bdc001ce96c813229aa
- https://github.com/pydantic/pydantic/commit/80e0dd3f752bef145dce12f160d262bb40ec8d47
- https://github.com/pydantic/pydantic/commit/bdde15b7b947c94ca00fd6eb92da8db390a13520
- https://github.com/pydantic/pydantic
- https://github.com/pypa/advisory-database/tree/main/vulns/pydantic/PYSEC-2021-47.yaml
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/S2HT266L6Q7H6ICP7DFGXOGBJHNNKMKB
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UEFWM7DYKD2ZHE7R5YT5EQWJPV4ZKYRB
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UMKAJX4O6IGBBCE32CO2G7PZQCCQSBLV
- CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L- Weakness (CWE)
CWE-835- Platform
- Python (PyPI)
- Package
pydantic- Disclosed
- 13.05.2021
- Updated
- 11.10.2026 13:19
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2021-47 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-5jqp-qgf6-3pvh - CC BY 4.0
Vulnerability history: pydantic
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 05.2021 04.2024
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Medium 2
Disclosures per year
- 2021: 1
- 2022: 0
- 2023: 0
- 2024: 1
- 2025: 0
- 2026: 0
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Use of "infinity" as an input to datetime and date fields causes infinite loop in pydantic this entry
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