---
id: CVE-2021-29063
aliases:
  - GHSA-f865-m6cq-j9vx
  - PYSEC-2021-427
title: ReDOS in Mpmath
summary: ReDOS in Mpmath
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
vendor: mpmath
product: mpmath
ecosystem: pip
affected:
  - mpmath < 1.3.0
patched:
  - mpmath 1.3.0
published: '2021-08-09'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:49:07.864685752Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-f865-m6cq-j9vx'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2021-29063'
  - url: 'https://github.com/fredrik-johansson/mpmath/issues/548'
  - url: 'https://github.com/mpmath/mpmath/pull/570'
  - url: 'https://github.com/npm/hosted-git-info/pull/76'
  - url: >-
      https://github.com/fredrik-johansson/mpmath/commit/46d44c3c8f3244017fe1eb102d564eb4ab8ef750
  - url: >-
      https://github.com/fredrik-johansson/mpmath/commit/c811b37c65a4372a7ce613111d2a508c204f9833
  - url: >-
      https://github.com/mpmath/mpmath/commit/c811b37c65a4372a7ce613111d2a508c204f9833
  - url: 'https://www.npmjs.com/package/hosted-git-info'
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MS2U6GLXQSRZJE2HVUAUMVFR2DWQLCZG
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/EIUX3XWY2K3MSO7QXMZXQQYAURARSPC5
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3M5O55E7VUDMXCPQR6MQTOIFDKHP36AA
  - url: 'https://github.com/yetingli/SaveResults/blob/main/js/hosted-git-info.js'
  - url: 'https://github.com/yetingli/PoCs/blob/main/CVE-2021-29063/Mpmath.md'
  - url: >-
      https://github.com/pypa/advisory-database/tree/main/vulns/mpmath/PYSEC-2021-427.yaml
  - url: 'https://github.com/mpmath/mpmath/releases/tag/1.3.0'
  - url: 'https://github.com/fredrik-johansson/mpmath'
  - url: 'https://github.com/advisories/GHSA-f865-m6cq-j9vx'
tags:
  - osv
  - pip
epss: 0.04179
epssPercentile: 0.90529
ingestedAt: '2026-09-12T03:13:01.690Z'
---

## Overview

A Regular Expression Denial of Service (ReDOS) vulnerability was discovered in Mpmath v1.0.0 when the mpmathify function is called.

## Affected packages

- `mpmath < 1.3.0`

## Remediation

Upgrade to a patched release:

- `mpmath 1.3.0`