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Python pip: Prior to 1.2.1, there is an Out-of-bounds read/crash on Unpacker reuse after a caught error, potentially leading to a DoS attack. (CVE-2026-57585)

0
Medium
VulnerabilityCVE-2026-57585gcveosvcleanstart-2026-wi70284cve-2026-57585alpinecleanstart-2026-el29865cleanstartcsafsuse-product-security-teambrew-locust-cve-2026-57585homebrewbrew-pdm-cve-2026-57585brew-pip-audit-cve-2026-57585brew-poetry-cve-2026-57585ubuntu-cve-2026-57585ubuntu-pro-14-04-ltsubuntu-pro-16-04-ltsubuntu-18-04-ltsubuntu-pro-18-04-ltsubuntu-20-04-ltsubuntu-pro-20-04-ltsubuntu-22-04-ltsubuntu-pro-22-04-ltsubuntu-24-04-ltsubuntu-pro-24-04-ltsubuntu-25-10ubuntu-26-10ubuntu-26-04-ltsubuntu-pro-26-04-lts
Published: 06/30/2026 (06/30/2026, 22:16:00 UTC)
Source: GCVE Database
Product: python-pip

Description

A vulnerability in the Pdm MessagePack for Python library prior to version 1.2.1 allows an out-of-bounds read and process crash when the Unpacker object is reused after an error occurs. This can lead to denial-of-service (DoS) conditions if untrusted input is repeatedly unpacked. The issue is fixed in version 1.2.1. Users should avoid reusing the same Unpacker after an error and instead create a new one to prevent crashes.

CVSS v3.1

Score 7.5high

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected software

Alpineghsa
py3.11-pip
Affected versions
<26.2-r1=26.2-r1
Homebrewmore threats →ghsa
locust
pkg:brew/locust
Affected versions
>=2.2.1 <2.44.4
Homebrewmore threats →ghsa
pdm
pkg:brew/pdm
Affected versions
<2.28.1
Homebrewmore threats →ghsa
pip-audit
pkg:brew/pip-audit
Affected versions
>=1.0.1 <2.10.1_1
Homebrewmore threats →ghsa
poetry
pkg:brew/poetry
Affected versions
>=1.0.0 <2.4.1_4
Ubuntu:Pro:14.04:LTSmore threats →ghsa
python-pip
pkg:deb/ubuntu/python-pip?arch=source&distro=esm-infra-legacy/trusty
Affected versions
=1.4.1-2=1.5.4-1=1.5.4-1ubuntu1=1.5.4-1ubuntu3=1.5.4-1ubuntu4=1.5.4-1ubuntu4+esm1=1.5.4-1ubuntu4+esm2=1.5.4-1ubuntu4+esm3=1.5.4-1ubuntu4+esm4=1.5.4-1ubuntu4+esm5
Ubuntu:Pro:16.04:LTSmore threats →ghsa
python-pip
pkg:deb/ubuntu/python-pip?arch=source&distro=esm-apps/xenial
Affected versions
=1.5.6-7ubuntu1=1.5.6-7ubuntu2=8.0.2-7=8.0.3-1=8.0.3-2=8.1.0-1=8.1.0-2=8.1.1-1=8.1.1-2=8.1.1-2ubuntu0.1=8.1.1-2ubuntu0.2=8.1.1-2ubuntu0.4=8.1.1-2ubuntu0.6=8.1.1-2ubuntu0.6+esm2=8.1.1-2ubuntu0.6+esm3=8.1.1-2ubuntu0.6+esm4=8.1.1-2ubuntu0.6+esm5=8.1.1-2ubuntu0.6+esm6=8.1.1-2ubuntu0.6+esm8=8.1.1-2ubuntu0.6+esm10=8.1.1-2ubuntu0.6+esm11=8.1.1-2ubuntu0.6+esm12
Ubuntu:18.04:LTSmore threats →ghsa
python-msgpack
pkg:deb/ubuntu/python-msgpack?arch=source&distro=bionic
Affected versions
=0.5.4-0ubuntu2=0.5.6-0ubuntu1=0.5.6-1
Ubuntu:Pro:18.04:LTSmore threats →ghsa
python-pip
pkg:deb/ubuntu/python-pip?arch=source&distro=esm-apps/bionic
Affected versions
=9.0.1-2=9.0.1-2.3~ubuntu1=9.0.1-2.3~ubuntu1.18.04.1=9.0.1-2.3~ubuntu1.18.04.2=9.0.1-2.3~ubuntu1.18.04.3=9.0.1-2.3~ubuntu1.18.04.4=9.0.1-2.3~ubuntu1.18.04.5=9.0.1-2.3~ubuntu1.18.04.5+esm2=9.0.1-2.3~ubuntu1.18.04.5+esm3=9.0.1-2.3~ubuntu1.18.04.6=9.0.1-2.3~ubuntu1.18.04.6+esm1=9.0.1-2.3~ubuntu1.18.04.7=9.0.1-2.3~ubuntu1.18.04.7+esm1=9.0.1-2.3~ubuntu1.18.04.8=9.0.1-2.3~ubuntu1.18.04.8+esm1=9.0.1-2.3~ubuntu1.18.04.8+esm2=9.0.1-2.3~ubuntu1.18.04.8+esm4=9.0.1-2.3~ubuntu1.18.04.8+esm6=9.0.1-2.3~ubuntu1.18.04.8+esm7=9.0.1-2.3~ubuntu1.18.04.8+esm8
Ubuntu:20.04:LTSmore threats →ghsa
python-msgpack
pkg:deb/ubuntu/python-msgpack?arch=source&distro=focal
Affected versions
=0.5.6-1build2=0.5.6-1ubuntu1=0.5.6-2=0.5.6-3=0.5.6-3build1=0.6.2-1
Ubuntu:Pro:20.04:LTSmore threats →ghsa
python-pip
pkg:deb/ubuntu/python-pip?arch=source&distro=esm-apps/focal
Affected versions
=18.1-5=18.1-5build1=18.1-5ubuntu1=20.0.2-2=20.0.2-4=20.0.2-5=20.0.2-5ubuntu1=20.0.2-5ubuntu1.1=20.0.2-5ubuntu1.3=20.0.2-5ubuntu1.4=20.0.2-5ubuntu1.5=20.0.2-5ubuntu1.6=20.0.2-5ubuntu1.7=20.0.2-5ubuntu1.8=20.0.2-5ubuntu1.9=20.0.2-5ubuntu1.10=20.0.2-5ubuntu1.10+esm2=20.0.2-5ubuntu1.11=20.0.2-5ubuntu1.11+esm2=20.0.2-5ubuntu1.11+esm3=20.0.2-5ubuntu1.11+esm4
Ubuntu:22.04:LTSmore threats →ghsa
python-msgpack
pkg:deb/ubuntu/python-msgpack?arch=source&distro=jammy
Affected versions
=1.0.0-6build1=1.0.0-6build2=1.0.2-2=1.0.3-1=1.0.3-1build1
Ubuntu:Pro:22.04:LTSmore threats →ghsa
python-pip
pkg:deb/ubuntu/python-pip?arch=source&distro=esm-apps/jammy
Affected versions
=20.3.4-4=21.3.1+dfsg-3=22.0.2+dfsg-1=22.0.2+dfsg-1ubuntu0.1=22.0.2+dfsg-1ubuntu0.2=22.0.2+dfsg-1ubuntu0.3=22.0.2+dfsg-1ubuntu0.4=22.0.2+dfsg-1ubuntu0.5=22.0.2+dfsg-1ubuntu0.6=22.0.2+dfsg-1ubuntu0.7=22.0.2+dfsg-1ubuntu0.7+esm1=22.0.2+dfsg-1ubuntu0.7+esm2=22.0.2+dfsg-1ubuntu0.7+esm3
Ubuntu:24.04:LTSmore threats →ghsa
python-msgpack
pkg:deb/ubuntu/python-msgpack?arch=source&distro=noble
Affected versions
=1.0.3-3=1.0.3-3build1=1.0.3-3build2
Ubuntu:24.04:LTSmore threats →ghsa
python-srsly
pkg:deb/ubuntu/python-srsly?arch=source&distro=noble
Affected versions
=2.4.5-1build1=2.4.5-1build2=2.4.5-1ubuntu1
Ubuntu:Pro:24.04:LTSmore threats →ghsa
python-pip
pkg:deb/ubuntu/python-pip?arch=source&distro=esm-apps/noble
Affected versions
=23.2+dfsg-1=23.3+dfsg-1=24.0+dfsg-1=24.0+dfsg-1ubuntu1=24.0+dfsg-1ubuntu1.1=24.0+dfsg-1ubuntu1.2=24.0+dfsg-1ubuntu1.3=24.0+dfsg-1ubuntu1.3+esm1=24.0+dfsg-1ubuntu1.3+esm2=24.0+dfsg-1ubuntu1.3+esm3
Ubuntu:25.10more threats →ghsa
python-msgpack
pkg:deb/ubuntu/python-msgpack?arch=source&distro=questing
Affected versions
=1.0.3-3build4
Ubuntu:25.10more threats →ghsa
python-pip
pkg:deb/ubuntu/python-pip?arch=source&distro=questing
Affected versions
=25.0+dfsg-1=25.1.1+dfsg-1=25.1.1+dfsg-1ubuntu1=25.1.1+dfsg-1ubuntu2
Ubuntu:25.10more threats →ghsa
python-srsly
pkg:deb/ubuntu/python-srsly?arch=source&distro=questing
Affected versions
=2.5.1-1
Ubuntu:26.10more threats →ghsa
python-msgpack
pkg:deb/ubuntu/python-msgpack?arch=source&distro=stonking
Affected versions
=1.1.2-2build1=1.1.2-4
Ubuntu:26.10more threats →ghsa
python-pip
pkg:deb/ubuntu/python-pip?arch=source&distro=stonking
Affected versions
=25.1.1+dfsg-1ubuntu2=26.1.2+dfsg-1
Ubuntu:26.10more threats →ghsa
python-srsly
pkg:deb/ubuntu/python-srsly?arch=source&distro=stonking
Affected versions
=2.5.2-2build1
Ubuntu:26.04:LTSmore threats →ghsa
python-msgpack
pkg:deb/ubuntu/python-msgpack?arch=source&distro=resolute
Affected versions
=1.0.3-3build4=1.0.3-3build5=1.1.2-1=1.1.2-2=1.1.2-2build1
Ubuntu:26.04:LTSmore threats →ghsa
python-srsly
pkg:deb/ubuntu/python-srsly?arch=source&distro=resolute
Affected versions
=2.5.1-1=2.5.2-2=2.5.2-2build1
Ubuntu:Pro:26.04:LTSmore threats →ghsa
python-pip
pkg:deb/ubuntu/python-pip?arch=source&distro=esm-apps/resolute
Affected versions
=25.1.1+dfsg-1ubuntu2=25.1.1+dfsg-1ubuntu2+esm1=25.1.1+dfsg-1ubuntu2+esm2=25.1.1+dfsg-1ubuntu2+esm3

Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 10/18/2026, 04:41:36 UTC

Technical Analysis

The vulnerability (CVE-2026-57585) affects the Pdm MessagePack for Python library used by python-pip. It causes an out-of-bounds read and process crash when the Unpacker object is reused after a caught error. This flaw can be triggered by repeatedly unpacking untrusted input, potentially causing a denial-of-service (DoS) attack. The issue has been addressed and fixed in version 1.2.1 of the library. Users are advised to avoid reusing the same Unpacker instance after an error and instead instantiate a new Unpacker to prevent crashes.

Potential Impact

The vulnerability can cause denial-of-service conditions by crashing the process when the Unpacker object is reused after an error. There is no indication of confidentiality or integrity impact. The CVSS score is 7.5 (medium severity) with an impact primarily on availability.

Mitigation Recommendations

A fix is available in version 1.2.1 of the Pdm MessagePack library. Users should upgrade to version 1.2.1 or later. Until upgraded, users should avoid reusing the same Unpacker object after an error and create a new Unpacker instance instead to prevent crashes.

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Technical Details

Gcve Source
db.gcve.eu
Osv Id
CLEANSTART-2026-WI70284
Osv Schema Version
1.7.3
Ecosystems
["Alpine"]
State
PUBLISHED

Threat ID: 6a984546acd9273b496aafbd

Added to database: 09/02/2026, 15:48:22 UTC

Last enriched: 10/18/2026, 04:41:36 UTC

Last updated: 10/18/2026, 18:48:22 UTC

Views: 47

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