USN-8744-1: Python vulnerabilities

It was discovered that Python's http.cookies module incorrectly handled control characters in certain cookie operations. An attacker could possibly use this issue to inject arbitrary content. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-3644) It was discovered that the Python pyexpat module was vulnerable to unbounded recursion in the Expat XML parser. An attacker could possibly use this issue to cause Python to crash, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-4224) It was discovered that Python's tarfile module did not correctly apply the filter parameter when extracting hard links. An attacker could possibly use this issue to cause files to be extracted with an unexpected uid or gid, bypassing the restrictions requested via filter='data'. (CVE-2026-4360) It was discovered that Python's http.cookies module incorrectly escaped values in the js_output() method. An attacker could possibly use this issue to inject arbitrary JavaScript. (CVE-2026-6019) It was discovered that Python's html.parser module incorrectly handled repeated unterminated markup declarations. An attacker could possibly use this issue to cause Python to consume excessive CPU resources, leading to a denial of service. (CVE-2026-15308)