{"id":"UBUNTU-CVE-2026-121969","details":"netrek-client-cow through 3.3.3 contains a stack-based buffer overflow vulnerability in handleSMessage() in short.c that allows malicious servers to overflow a 100-byte stack buffer by sending oversized SP_S_MESSAGE packets. A malicious Netrek server or man-in-the-middle on the plaintext TCP connection can send overlong or unterminated message bodies to write server-controlled bytes onto the stack and crash the client.","modified":"2026-11-06T01:00:36.925511558Z","published":"2026-11-05T00:00:00Z","upstream":["CVE-2026-121969"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-121969"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-121969"},{"type":"REPORT","url":"https://github.com/quozl/netrek-client-cow"},{"type":"REPORT","url":"https://github.com/quozl/netrek-client-cow/blob/3.3.3/short.c#L949"},{"type":"REPORT","url":"https://github.com/quozl/netrek-client-cow/commit/fb322e74abee3b0b76a9c5a31df6aab5585d3127"},{"type":"REPORT","url":"https://github.com/quozl/netrek-client-cow/issues/11"},{"type":"REPORT","url":"https://www.vulncheck.com/advisories/netrek-client-cow-through-3.3.3-stack-buffer-overflow-via-handlesmessage"}],"affected":[{"package":{"name":"netrek-client-cow","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/netrek-client-cow?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.0-3.1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.3.0-3.1","binary_name":"netrek-client-cow"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-121969.json"}},{"package":{"name":"netrek-client-cow","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/netrek-client-cow?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.1-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.3.1-1","binary_name":"netrek-client-cow"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-121969.json"}},{"package":{"name":"netrek-client-cow","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/netrek-client-cow?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.1-4build1"],"ecosystem_specific":{"binaries":[{"binary_name":"netrek-client-cow","binary_version":"3.3.1-4build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-121969.json"}},{"package":{"name":"netrek-client-cow","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/netrek-client-cow?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.2-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.3.2-1","binary_name":"netrek-client-cow"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-121969.json"}},{"package":{"name":"netrek-client-cow","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/netrek-client-cow?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.2-1","3.3.2-1build1","3.3.2-1build2"],"ecosystem_specific":{"binaries":[{"binary_version":"3.3.2-1build2","binary_name":"netrek-client-cow"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-121969.json"}},{"package":{"name":"netrek-client-cow","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/netrek-client-cow?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.2-1build3","3.3.3-1"],"ecosystem_specific":{"binaries":[{"binary_name":"netrek-client-cow","binary_version":"3.3.3-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-121969.json"}},{"package":{"name":"netrek-client-cow","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/netrek-client-cow?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.2-1build2","3.3.2-1build3"],"ecosystem_specific":{"binaries":[{"binary_name":"netrek-client-cow","binary_version":"3.3.2-1build3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-121969.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"},{"type":"Ubuntu","score":"medium"}]}