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Vulnerability record · CVE-2018-20406 · published 23 December 2018

CVE-2018-20406: Python integer overflow vulnerability

Python · Python

Modules/_pickle.c in Python before 3.7.1 has an integer overflow via a large LONG_BINPUT value that is mishandled during a "resize to twice the size" attempt. This issue might cause memory exhaustion, but is only relevant if the pickle format is used for serializing tens or hundreds of gigabytes of data. This issue is fixed in: v3.4.10, v3.4.10rc1; v3.5.10, v3.5.10rc1, v3.5.7, v3.5.7rc1, v3.5.8, v3.5.8rc1, v3.5.8rc2, v3.5.9; v3.6.10, v3.6.10rc1, v3.6.11, v3.6.11rc1, v3.6.12, v3.6.7, v3.6.7rc1, v3.6.7rc2, v3.6.8, v3.6.8rc1, v3.6.9, v3.6.9rc1; v3.7.1, v3.7.1rc1, v3.7.1rc2, v3.7.2, v3.7.2rc1, v3.7.3, v3.7.3rc1, v3.7.4, v3.7.4rc1, v3.7.4rc2, v3.7.5, v3.7.5rc1, v3.7.6, v3.7.6rc1, v3.7.7, v3.7.7rc1, v3.7.8, v3.7.8rc1, v3.7.9.

7.5 CVSS 3.0 High EPSS 5.8% · top 7.2% CWE-190 · Integer overflow
7.5CVSS 3.0 base score, v2 5.0
5.8%EPSS exploitation probability, 30 days
NoNot in CISA KEV
3Affected product versions listed by NVD
30References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

Modules/_pickle.c in Python before 3.7.1 has an integer overflow via a large LONG_BINPUT value that is mishandled during a "resize to twice the size" attempt. This issue might cause memory exhaustion, but is only relevant if the pickle format is used for serializing tens or hundreds of gigabytes of data. This issue is fixed in: v3.4.10, v3.4.10rc1; v3.5.10, v3.5.10rc1, v3.5.7, v3.5.7rc1, v3.5.8, v3.5.8rc1, v3.5.8rc2, v3.5.9; v3.6.10, v3.6.10rc1, v3.6.11, v3.6.11rc1, v3.6.12, v3.6.7, v3.6.7rc1, v3.6.7rc2, v3.6.8, v3.6.8rc1, v3.6.9, v3.6.9rc1; v3.7.1, v3.7.1rc1, v3.7.1rc2, v3.7.2, v3.7.2rc1, v3.7.3, v3.7.3rc1, v3.7.4, v3.7.4rc1, v3.7.4rc2, v3.7.5, v3.7.5rc1, v3.7.6, v3.7.6rc1, v3.7.7, v3.7.7rc1, v3.7.8, v3.7.8rc1, v3.7.9.

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

3 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html
https://access.redhat.com/errata/RHSA-2019:3725
https://bugs.python.org/issue34656 ExploitIssue TrackingPatchVendor Advisory
https://github.com/python/cpython/commit/a4ae828ee416a66d8c7bf5ee71d653c2cc6a26dd PatchThird Party Advisory
https://lists.debian.org/debian-lts-announce/2019/02/msg00011.html Mailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/46PVWY5LFP4BRPG3BVQ5QEE
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AEZ5IQT7OF7Q2NCGIVABOWY
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/D3LXPABKVLFYUHRYJPM3CSS
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ICBEGRHIPHWPG2VGYS6R4EV
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JSKPGPZQNTAULHW4UH63KGO
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TR6GCO3WTV4D5L23WTCBF27
https://security.netapp.com/advisory/ntap-20190416-0010/
https://usn.ubuntu.com/4127-1/
https://usn.ubuntu.com/4127-2/
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html
https://access.redhat.com/errata/RHSA-2019:3725
https://bugs.python.org/issue34656 ExploitIssue TrackingPatchVendor Advisory
https://github.com/python/cpython/commit/a4ae828ee416a66d8c7bf5ee71d653c2cc6a26dd PatchThird Party Advisory
https://lists.debian.org/debian-lts-announce/2019/02/msg00011.html Mailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/46PVWY5LFP4BRPG3BVQ5QEE
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AEZ5IQT7OF7Q2NCGIVABOWY
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/D3LXPABKVLFYUHRYJPM3CSS
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ICBEGRHIPHWPG2VGYS6R4EV
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JSKPGPZQNTAULHW4UH63KGO
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TR6GCO3WTV4D5L23WTCBF27
https://security.netapp.com/advisory/ntap-20190416-0010/
https://usn.ubuntu.com/4127-1/
https://usn.ubuntu.com/4127-2/

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Source: NIST National Vulnerability Database (record CVE-2018-20406), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.