{"id":"UBUNTU-CVE-2026-4271","details":"A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application attempting to access memory that has already been freed, potentially causing application instability or crashes, resulting in a Denial of Service (DoS).","modified":"2026-10-22T04:41:56.790963273Z","published":"2026-03-17T12:16:00Z","related":["USN-8890-1","USN-8890-2"],"upstream":["CVE-2026-4271"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-4271"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-4271"},{"type":"REPORT","url":"https://gitlab.gnome.org/GNOME/libsoup/-/issues/496"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8890-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8890-2"}],"affected":[{"package":{"name":"libsoup3","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libsoup3?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.4.4-5ubuntu0.9"}]}],"versions":["3.4.2-4","3.4.4-1","3.4.4-2","3.4.4-4","3.4.4-5","3.4.4-5build1","3.4.4-5build2","3.4.4-5ubuntu0.1","3.4.4-5ubuntu0.2","3.4.4-5ubuntu0.3","3.4.4-5ubuntu0.4","3.4.4-5ubuntu0.5","3.4.4-5ubuntu0.6","3.4.4-5ubuntu0.7","3.4.4-5ubuntu0.8"],"ecosystem_specific":{"binaries":[{"binary_name":"gir1.2-soup-3.0","binary_version":"3.4.4-5ubuntu0.9"},{"binary_name":"libsoup-3.0-0","binary_version":"3.4.4-5ubuntu0.9"},{"binary_name":"libsoup-3.0-common","binary_version":"3.4.4-5ubuntu0.9"},{"binary_name":"libsoup-3.0-tests","binary_version":"3.4.4-5ubuntu0.9"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-4271.json"}},{"package":{"name":"libsoup3","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/libsoup3?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.6.5-1","3.6.5-1ubuntu1","3.6.5-3","3.6.5-4","3.6.5-4ubuntu0.1","3.6.5-4ubuntu0.2"],"ecosystem_specific":{"binaries":[{"binary_version":"3.6.5-4ubuntu0.2","binary_name":"gir1.2-soup-3.0"},{"binary_version":"3.6.5-4ubuntu0.2","binary_name":"libsoup-3.0-0"},{"binary_name":"libsoup-3.0-common","binary_version":"3.6.5-4ubuntu0.2"},{"binary_name":"libsoup-3.0-tests","binary_version":"3.6.5-4ubuntu0.2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-4271.json"}},{"package":{"name":"libsoup3","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/libsoup3?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.6.6-1ubuntu3"}]}],"versions":["3.6.6-1"],"ecosystem_specific":{"binaries":[{"binary_name":"gir1.2-soup-3.0","binary_version":"3.6.6-1ubuntu3"},{"binary_version":"3.6.6-1ubuntu3","binary_name":"libsoup-3.0-0"},{"binary_name":"libsoup-3.0-common","binary_version":"3.6.6-1ubuntu3"},{"binary_version":"3.6.6-1ubuntu3","binary_name":"libsoup-3.0-tests"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-4271.json"}},{"package":{"name":"libsoup3","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libsoup3?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.6.6-1ubuntu0.1"}]}],"versions":["3.6.5-4","3.6.5-5","3.6.5-6","3.6.5-7","3.6.5-9","3.6.6-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.6.6-1ubuntu0.1","binary_name":"gir1.2-soup-3.0"},{"binary_version":"3.6.6-1ubuntu0.1","binary_name":"libsoup-3.0-0"},{"binary_version":"3.6.6-1ubuntu0.1","binary_name":"libsoup-3.0-common"},{"binary_name":"libsoup-3.0-tests","binary_version":"3.6.6-1ubuntu0.1"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-4271.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}