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CRITICAL

CVE-2020-36242

CVSS v3

9.1

CRITICAL

EPSS Score

6.7 %

exploit probability, as of 2026-10-19

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • cryptographyPyPIfrom 3.1 · fixed in 3.3.2

Vendor advisories

  • CVE-2020-36242 Red Hat Product Security141 products fixed · 13 known affected

    python-cryptography: Large inputs for symmetric encryption can trigger integer overflow leading to buffer overflow

    cryptography.src as a component of Red Hat Ansible Automation Platform 1.2 · python-cryptography.src as a component of Red Hat Ansible Automation Platform 1.2 · python-cryptography.src as a component of Red Hat Ansible Engine 2

  • RHSA-2021:3254 Red Hat Product Security126 products fixed

    Red Hat Security Advisory: rh-python38 security, bug fix, and enhancement update

  • RHSA-2021:2239 Red Hat Product Security2 products fixed

    Red Hat Security Advisory: Red Hat Virtualization Host security update [ovirt-4.4.6]

  • RHSA-2021:1608 Red Hat Product Security13 products fixed

    Red Hat Security Advisory: python-cryptography security, bug fix, and enhancement update

Full record on NVD

Description

In the cryptography package before 3.3.2 for Python, certain sequences of update calls to symmetrically encrypt multi-GB values could result in an integer overflow and buffer overflow, as demonstrated by the Fernet class.

Technical details

Published
2021-02-07

Frequently asked questions

What is CVE-2020-36242?

In the cryptography package before 3.3.2 for Python, certain sequences of update calls to symmetrically encrypt multi-GB values could result in an integer overflow and buffer overflow, as demonstrated by the Fernet class.

Is CVE-2020-36242 actively exploited?

Active exploitation of CVE-2020-36242 has not been confirmed. Its EPSS score was 6.7% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-36242?

CVE-2020-36242 has a CVSS v3 base score of 9.1 (CRITICAL severity).

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