--- title: "CVE-2018-20406\n | Ubuntu" description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/CVE-2018-20406?format=md keywords: index, follow --- # CVE-2018-20406 Publication date 23 December 2018 Last updated 25 August 2025 --- Ubuntu priority **Low** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) ## Cvss 3 Severity Score **7.5 · High** [Score breakdown](https://ubuntu.com/security/CVE-2018-20406?format=md#impact-score) Toggle side navigation ## 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. [Read the notes from the security team](https://ubuntu.com/security/CVE-2018-20406?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | python2.7 | 24.10 oracular | Not in release | | 24.04 LTS noble | Not in release | | 23.10 mantic | Not in release | | 23.04 lunar | Not in release | | 22.10 kinetic | Not affected | | 22.04 LTS jammy | Not affected | | 21.10 impish | Not affected | | 21.04 hirsute | Not affected | | 20.10 groovy | Not affected | | 20.04 LTS focal | Not affected | | 19.10 eoan | Not affected | | 19.04 disco | Not affected | | 18.10 cosmic | Not affected | | 18.04 LTS bionic | Not affected | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not affected | | python3.4 | 24.10 oracular | Not in release | | 24.04 LTS noble | Not in release | | 23.10 mantic | Not in release | | 23.04 lunar | Not in release | | 22.10 kinetic | Not in release | | 22.04 LTS jammy | Not in release | | 21.10 impish | Not in release | | 21.04 hirsute | Not in release | | 20.10 groovy | Not in release | | 20.04 LTS focal | Not in release | | 19.10 eoan | Not in release | | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Fixed 3.4.3-1ubuntu1~14.04.7+esm2 Ubuntu Pro | | python3.5 | 24.10 oracular | Not in release | | 24.04 LTS noble | Not in release | | 23.10 mantic | Not in release | | 23.04 lunar | Not in release | | 22.10 kinetic | Not in release | | 22.04 LTS jammy | Not in release | | 21.10 impish | Not in release | | 21.04 hirsute | Not in release | | 20.10 groovy | Not in release | | 20.04 LTS focal | Not in release | | 19.10 eoan | Not in release | | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Fixed 3.5.2-2ubuntu0~16.04.8 | | 14.04 LTS trusty | Fixed 3.5.2-2ubuntu0~16.04.4~14.04.1+esm1 Ubuntu Pro | | python3.6 | 24.10 oracular | Not in release | | 24.04 LTS noble | Not in release | | 23.10 mantic | Not in release | | 23.04 lunar | Not in release | | 22.10 kinetic | Not in release | | 22.04 LTS jammy | Not in release | | 21.10 impish | Not in release | | 21.04 hirsute | Not in release | | 20.10 groovy | Not in release | | 20.04 LTS focal | Not in release | | 19.10 eoan | Not in release | | 19.04 disco | Not in release | | 18.10 cosmic | Fixed 3.6.7-1~18.10 | | 18.04 LTS bionic | Fixed 3.6.7-1~18.04 | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | python3.7 | 24.10 oracular | Not in release | | 24.04 LTS noble | Not in release | | 23.10 mantic | Not in release | | 23.04 lunar | Not in release | | 22.10 kinetic | Not in release | | 22.04 LTS jammy | Not in release | | 21.10 impish | Not in release | | 21.04 hirsute | Not in release | | 20.10 groovy | Not in release | | 20.04 LTS focal | Not in release | | 19.10 eoan | Not affected | | 19.04 disco | Not affected | | 18.10 cosmic | Not affected | | 18.04 LTS bionic | Not affected | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | --- * [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) * [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses) * [Patch details](https://ubuntu.com/security/CVE-2018-20406?format=md#patch-details) ### Get expanded security coverage with Ubuntu Pro Reduce your average CVE exposure time from 98 days to 1 day with expanded CVE patching, ten-years security maintenance and optional support for the full stack of open-source applications. Free for personal use. [Get Ubuntu Pro](https://ubuntu.com/pro) [30-day free trial](https://ubuntu.com/pro/free-trial) ## Notes --- ### [mdeslaur](https://launchpad.net/~mdeslaur) bug says 2.7 is not affected ### Patch details For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) | Package | Patch details | | --- | --- | | python3.4 | * Upstream: [4b42d57](https://github.com/python/cpython/commit/4b42d575bf0fb01192b3ec54b7e224b238691527) | | python3.5 | * Upstream: [ef33dd6](https://github.com/python/cpython/commit/ef33dd6036aafbd3f06c1d56e2b1a81dae3da63c) | | python3.6 | * Upstream: [71a9c65](https://github.com/python/cpython/commit/71a9c65e74a70b6ed39adc4ba81d311ac1aa2acc) | | python3.7 | * Upstream: [ef4306b](https://github.com/python/cpython/commit/ef4306b24c9034d6b37bb034e2ebe82e745d4b77) | ## Severity score breakdown CVSS version: CVSS v3.0 **Base score** 7.5 · High * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Network | | Attack complexity | Low | | Privileges required | None | | User interaction | None | | Scope | Unchanged | | Confidentiality impact | None | | Integrity impact | None | | Availability impact | High | * Scores | Parameter | Value | | --- | --- | | Base score | 7.5 · High | | Exploitability score | - | | Impact score | - | **Vector:** CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20406) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2018-20406) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2018-20406) * [Debian](https://security-tracker.debian.org/tracker/CVE-2018-20406) ### Related Ubuntu Security Notices (USN) + [USN-4127-1](https://usn.ubuntu.com/USN-4127-1) + Python vulnerabilities + 9 September 2019 + [USN-4127-2](https://usn.ubuntu.com/USN-4127-2) + Python vulnerabilities + 10 September 2019 + [USN-6891-1](https://usn.ubuntu.com/USN-6891-1) + Python vulnerabilities + 11 July 2024 ### Other references * *