{"id":"CVE-2026-68119","aliases":[],"url":"https://o3.security/vulnerability/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.","published":"2026-08-10T11:58:39.026Z","modified":"2026-08-14T04:03:55.274581911Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.12.101"}],"fix":null,"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"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-14T04:03:55.274581911Z"}}