7.5

CVE-2021-29510: Use of "infinity" as an input to datetime and date fields causes infinite loop in pydantic

Modified
AliasesGHSA-5jqp-qgf6-3pvhPYSEC-2021-47UBUNTU-CVE-2021-29510
Published 13-05-2021Last modified 03-08-2024

Vulnerability summary

CVE-2021-29510 is a high (CVSS 7.5) Loop with Unreachable Exit Condition vulnerability in fedoraproject fedora. EPSS estimates a 0.97% chance of exploitation in the next 30 days, higher than 62.1% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 3.3, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
0.97%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
OPENSUSE-SU-2026:11424-1

Timeline

  1. 13-05-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

Pydantic is a data validation and settings management using Python type hinting. In affected versions 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). Pydantic has been patched with fixes available in the following versions: v1.8.2, v1.7.4, v1.6.2. All these versions are available on pypi(https://pypi.org/project/pydantic/#history), and will be available on conda-forge(https://anaconda.org/conda-forge/pydantic) soon. See the changelog(https://pydantic-docs.helpmanual.io/) for details. If you absolutely can't upgrade, you can work around this risk using a validator(https://pydantic-docs.helpmanual.io/usage/validators/) to catch these values. 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 at https://github.com/samuelcolvin/pydantic/issues requesting a back-port, and we will endeavour to release a patch for earlier versions of pydantic.

CVSS metrics

7 scores · 5 sources · 3 versions

EPSS trend

Probability

0.97%

Chance of exploitation in the next 30 days

Percentile

62%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.97% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.

Debian1 product
  • pydantic< 1.7.4-1
Fedoraproject1 product
Pydantic1 product
  • pydantic< 1.6.2 | ≥ 1.7, < 1.7.4 | ≥ 1.8, < 1.8.2
PyPI1 product
  • pydantic< 1.6.2 | ≥ 1.7, < 1.7.4 | < 7e83fdd2563ffac081db7ecdf1affa65ef38c468 | ≥ 1.8, < 1.8.2
Samuelcolvin1 product
  • pydantic≥ 1.8.0, < 1.8.2 | ≥ 1.7.0, < 1.7.4 | < 1.6.2
Ubuntu1 product
  • pydantic< 1.2-1ubuntu0.1~esm1

6 vendors · 6 products

References

18 links
Show all 18 references