Ubuntu Security Notices USN-8524-1 USN-8524-1: Python vulnerability Publication date 9 July 2026 Overview Python could be made to crash if it received specially crafted input. Releases 16.04 LTS Open side navigation Close side navigation Packages Details Update instructions References Packages python2.7 - An interactive high-level object-oriented language python3.5 - An interactive high-level object-oriented language Details It was discovered that Python did not use sufficient entropy for Expat hash-flooding protection in the xml.parsers.expat and xml.etree.ElementTree modules. An attacker could use this to cause a denial of service via a crafted XML document. It was discovered that Python did not use sufficient entropy for Expat hash-flooding protection in the xml.parsers.expat and xml.etree.ElementTree modules. An attacker could use this to cause a denial of service via a crafted XML document. Update instructions In general, a standard system update will make all the necessary changes. Learn more about how to get the fixes. The problem can be corrected by updating your system to the following package versions: Ubuntu Release Package Version 16.04 LTS xenial idle-python2.7 – 2.7.12-1ubuntu0~16.04.18+esm20 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. idle-python3.5 – 3.5.2-2ubuntu0~16.04.13+esm23 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. libpython2.7 – 2.7.12-1ubuntu0~16.04.18+esm20 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. libpython2.7-dev – 2.7.12-1ubuntu0~16.04.18+esm20 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. libpython2.7-minimal – 2.7.12-1ubuntu0~16.04.18+esm20 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. libpython2.7-stdlib – 2.7.12-1ubuntu0~16.04.18+esm20 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. libpython2.7-testsuite – 2.7.12-1ubuntu0~16.04.18+esm20 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. libpython3.5 – 3.5.2-2ubuntu0~16.04.13+esm23 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. libpython3.5-dev – 3.5.2-2ubuntu0~16.04.13+esm23 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. libpython3.5-minimal – 3.5.2-2ubuntu0~16.04.13+esm23 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. libpython3.5-stdlib – 3.5.2-2ubuntu0~16.04.13+esm23 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. libpython3.5-testsuite – 3.5.2-2ubuntu0~16.04.13+esm23 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. python2.7 – 2.7.12-1ubuntu0~16.04.18+esm20 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. python2.7-dev – 2.7.12-1ubuntu0~16.04.18+esm20 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. python2.7-doc – 2.7.12-1ubuntu0~16.04.18+esm20 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. python2.7-examples – 2.7.12-1ubuntu0~16.04.18+esm20 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. python2.7-minimal – 2.7.12-1ubuntu0~16.04.18+esm20 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. python3.5 – 3.5.2-2ubuntu0~16.04.13+esm23 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. python3.5-dev – 3.5.2-2ubuntu0~16.04.13+esm23 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. python3.5-doc – 3.5.2-2ubuntu0~16.04.13+esm23 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. python3.5-examples – 3.5.2-2ubuntu0~16.04.13+esm23 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. python3.5-minimal – 3.5.2-2ubuntu0~16.04.13+esm23 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. python3.5-venv – 3.5.2-2ubuntu0~16.04.13+esm23 Ubuntu Pro Fix available with Ubuntu Pro via Legacy Support add-on. Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. Get Ubuntu Pro References CVE-2026-7210 CVE-2026-7210