{"id":"UBUNTU-CVE-2026-18238","details":"The rpcap client code that processes a RPCAP_MSG_PACKET message received from the server incorrectly validates its headers.  A malicious server can send a crafted message and cause the client to treat up to 20 bytes of the client process memory beyond the end of the buffer as if it was a part of the captured packet.","modified":"2026-09-16T14:01:36.121148395Z","published":"2026-09-05T19:16:00Z","upstream":["CVE-2026-18238"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-18238"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-18238"}],"affected":[{"package":{"name":"libpcap","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/libpcap?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.0-2","1.5.1-1","1.5.2-1","1.5.3-1","1.5.3-2","1.5.3-2ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libpcap0.8","binary_version":"1.5.3-2ubuntu0.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18238.json"}},{"package":{"name":"libpcap","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/libpcap?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.7.4-1","1.7.4-2","1.7.4-2ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libpcap0.8","binary_version":"1.7.4-2ubuntu0.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18238.json"}},{"package":{"name":"libpcap","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/libpcap?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.8.1-5ubuntu1","1.8.1-6ubuntu1","1.8.1-6ubuntu1.18.04.1","1.8.1-6ubuntu1.18.04.2"],"ecosystem_specific":{"binaries":[{"binary_version":"1.8.1-6ubuntu1.18.04.2","binary_name":"libpcap0.8"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18238.json"}},{"package":{"name":"libpcap","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libpcap?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.9.1-2","1.9.1-3","1.9.1-3ubuntu1.20.04.1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.9.1-3ubuntu1.20.04.1","binary_name":"libpcap0.8"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18238.json"}},{"package":{"name":"libpcap","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libpcap?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.0-2build1","1.10.1-4","1.10.1-4build1","1.10.1-4ubuntu1.22.04.1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.10.1-4ubuntu1.22.04.1","binary_name":"libpcap0.8"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18238.json"}},{"package":{"name":"libpcap","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libpcap?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.4-4","1.10.4-4ubuntu3","1.10.4-4.1ubuntu2","1.10.4-4.1ubuntu3"],"ecosystem_specific":{"binaries":[{"binary_name":"libpcap0.8t64","binary_version":"1.10.4-4.1ubuntu3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18238.json"}},{"package":{"name":"libpcap","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libpcap?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.5-2ubuntu2","1.10.5-2ubuntu3","1.10.6-1ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_name":"libpcap0.8t64","binary_version":"1.10.6-1ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-18238.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}