[USN-8087-3] python-cryptography vulnerability

========================================================================== Ubuntu Security Notice USN-8087-3 April 28, 2026 python-cryptography vulnerability ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 20.04 LTS - Ubuntu 18.04 LTS - Ubuntu 16.04 LTS Summary: python-cryptography could be made to expose sensitive information over the network. Software Description: - python-cryptography: Cryptography Python library Details: USN-8087-1 fixed a vulnerability in python-cryptography. This update provides the corresponding update to Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. Original advisory details: It was discovered that python-cryptography incorrectly handled subgroup validation for SECT curves. A remote attacker could use this issue to perform a subgroup attack and possibly recover the least significant bits of private keys. Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 20.04 LTS python-cryptography 2.8-3ubuntu0.3+esm2 Available with Ubuntu Pro python3-cryptography 2.8-3ubuntu0.3+esm2 Available with Ubuntu Pro Ubuntu 18.04 LTS python-cryptography 2.1.4-1ubuntu1.4+esm3 Available with Ubuntu Pro python3-cryptography 2.1.4-1ubuntu1.4+esm3 Available with Ubuntu Pro Ubuntu 16.04 LTS python-cryptography 1.2.3-1ubuntu0.3+esm3 Available with Ubuntu Pro python3-cryptography 1.2.3-1ubuntu0.3+esm3 Available with Ubuntu Pro In general, a standard system update will make all the necessary changes. References: https://ubuntu.com/security/notices/USN-8087-3 https://ubuntu.com/security/notices/USN-8087-2 https://ubuntu.com/security/notices/USN-8087-1 CVE-2026-26007