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Fencer Vulns
high 7.5

CVE-2021-29063 json

ReDOS in Mpmath

published 2021-06-21 5 y ago modified 2026-09-10 1 mo ago also GHSA-f865-m6cq-j9vx , PYSEC-2021-427 , EUVD-2021-0137

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.2%
EPSS 4.2% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

A Regular Expression Denial of Service (ReDOS) vulnerability was discovered in Mpmath v1.0.0 through v1.2.1 when the mpmathify function is called.

Patch / fix

  • pypi mpmath 1.3.0
  • mpmath Debian 14, Debian 13, Debian 12 1.2.1-2

debian advisories DEBIAN-CVE-2021-29063

  • mpmath Ubuntu Pro 16.04 LTS 0.19-3ubuntu0.1~esm1
  • mpmath Ubuntu Pro 18.04 LTS 1.0.0-1ubuntu0.1~esm1
  • mpmath Ubuntu Pro 20.04 LTS 1.1.0-2ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2021-29063

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python-mpmath openSUSE Tumbleweed 1.3.0-3.4

opensuse advisories openSUSE-SU-2026:12018-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-29063 updated cvss 7.5

python-mpmath: Regular expression denial of service in the mpmathify function

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

4.18% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/yetingli/PoCs/blob/main/CVE-2021-29063/Mpmath.md referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi mpmath
<1.3.0
1.3.0

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.