{"id":"UBUNTU-CVE-2026-120831","details":"A flaw was found in libslirp in if_output(). When moving a session from the fast queue to the batch queue, the code unlinked and reinserted an arbitrary packet via ifm-\u003em_nextpkt instead of the session queue head, corrupting queue pointers. A guest generating burst traffic could crash the host networking process, causing a denial of service.","modified":"2026-11-04T03:30:39.671832332Z","published":"2026-11-03T00:00:00Z","upstream":["CVE-2026-120831"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-120831"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-120831"},{"type":"REPORT","url":"https://access.redhat.com/security/cve/CVE-2026-120831"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2565425"},{"type":"REPORT","url":"https://gitlab.freedesktop.org/slirp/libslirp/-/commit/bad35bd3b529dc47aa109980a69a36da7848ab76"}],"affected":[{"package":{"name":"libslirp","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libslirp?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.0-1","4.0.0-2","4.1.0-1","4.1.0-2","4.1.0-2ubuntu1","4.1.0-2ubuntu2","4.1.0-2ubuntu2.1","4.1.0-2ubuntu2.2"],"ecosystem_specific":{"binaries":[{"binary_name":"libslirp0","binary_version":"4.1.0-2ubuntu2.2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-120831.json"}},{"package":{"name":"libslirp","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libslirp?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.4.0-1build1","4.6.1-1","4.6.1-1build1","4.6.1-1ubuntu0.2"],"ecosystem_specific":{"binaries":[{"binary_version":"4.6.1-1ubuntu0.2","binary_name":"libslirp0"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-120831.json"}},{"package":{"name":"libslirp","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libslirp?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.7.0-1ubuntu1","4.7.0-1ubuntu2","4.7.0-1ubuntu3","4.7.0-1ubuntu3.1"],"ecosystem_specific":{"binaries":[{"binary_version":"4.7.0-1ubuntu3.1","binary_name":"libslirp0"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-120831.json"}},{"package":{"name":"libslirp","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/libslirp?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.9.1-1ubuntu1","4.9.3-1ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_name":"libslirp0","binary_version":"4.9.3-1ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-120831.json"}},{"package":{"name":"libslirp","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libslirp?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.8.0-1ubuntu1","4.9.1-1ubuntu1","4.9.1-1ubuntu1.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libslirp0","binary_version":"4.9.1-1ubuntu1.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-120831.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}