{"id":"CVE-2026-68119","summary":"tcp: initialize standalone TCP-AO response padding","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: initialize standalone TCP-AO response padding\n\ntcp_v4_send_ack() and tcp_v6_send_response() construct standalone TCP\nresponses with TCP-AO options.  The option length carries the actual MAC\nlength, but the TCP header length includes the option rounded up to a\nfour-byte boundary.\n\ntcp_ao_hash_hdr() writes the MAC only.  Thus, when the MAC length is not\nfour-byte aligned, the one to three bytes after the MAC are left\nuninitialized and may be transmitted.  For the normal TCP-AO hashing\nmode, those bytes also have to be initialized before computing the MAC.\n\nInitialize only the alignment padding in the TCP-AO branches, before\nhashing the header.  Use TCPOPT_NOP, as in the normal TCP-AO output path.\nThis avoids adding work to non-AO TCP responses while preserving a valid\nauthenticated header.","modified":"2026-08-14T04:03:55.274581911Z","published":"2026-08-10T11:58:39.026Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68119.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/a859b280441fb02f64ed4037f03d5c0c34a7a595"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bbb7db8c74b0b5d17a695136f0f0806ecd0118f6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e1a9d3cc11829c5414a75eb39c704f461936eb24"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fadaff3f66e124c3a62237f9c881819a8ac90309"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68119.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68119"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"decde2586b34b99684faff1eab41e5c496c27fb6"},{"fixed":"bbb7db8c74b0b5d17a695136f0f0806ecd0118f6"},{"fixed":"fadaff3f66e124c3a62237f9c881819a8ac90309"},{"fixed":"a859b280441fb02f64ed4037f03d5c0c34a7a595"},{"fixed":"e1a9d3cc11829c5414a75eb39c704f461936eb24"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68119.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.101"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.42"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68119.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}