{"id":"USN-8952-2","summary":"python-tornado regression","details":"USN-8952-1 fixed vulnerabilities in Tornado. Unfortunately that update was incomplete due\nto an incomplete fix for CVE-2026-103263, which broke static file\nserving for applications that subclass Tornado's StaticFileHandler,\nsuch as Jupyter, and could introduce a regression. This update fixes the problem.\n\nWe apologize for the inconvenience.\n\nOriginal advisory details:\n\n It was discovered that Tornado did not properly handle certain HTTP requests\n and network inputs. An attacker could possibly use these issues to cause a\n denial of service, expose sensitive information, or bypass access controls.\n\n (CVE-2023-54397, CVE-2024-14029, CVE-2026-91990, CVE-2026-91992,\n CVE-2026-103262, CVE-2026-103263)","modified":"2026-11-07T01:58:36.964727875Z","published":"2026-11-06T15:04:17Z","related":["UBUNTU-CVE-2026-103263"],"upstream":["CVE-2026-103263","UBUNTU-CVE-2026-103263"],"references":[{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8952-2"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-103263"},{"type":"REPORT","url":"https://launchpad.net/bugs/2172317"}],"affected":[{"package":{"name":"python-tornado","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-infra-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.2.1-1ubuntu3.1+esm5"}]}],"versions":["4.2.1-1ubuntu2","4.2.1-1ubuntu3","4.2.1-1ubuntu3.1","4.2.1-1ubuntu3.1+esm1","4.2.1-1ubuntu3.1+esm2","4.2.1-1ubuntu3.1+esm3","4.2.1-1ubuntu3.1+esm4"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro with Legacy support add-on: 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