{"id":"CVE-2026-23247","summary":"tcp: secure_seq: add back ports to TS offset","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: secure_seq: add back ports to TS offset\n\nThis reverts 28ee1b746f49 (\"secure_seq: downgrade to per-host timestamp offsets\")\n\ntcp_tw_recycle went away in 2017.\n\nZhouyan Deng reported off-path TCP source port leakage via\nSYN cookie side-channel that can be fixed in multiple ways.\n\nOne of them is to bring back TCP ports in TS offset randomization.\n\nAs a bonus, we perform a single siphash() computation\nto provide both an ISN and a TS offset.","modified":"2026-04-14T03:48:37.895365Z","published":"2026-03-18T10:05:09.353Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23247.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/165573e41f2f66ef98940cf65f838b2cb575d9d1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/46e5b0d7cf55821527adea471ffe52a5afbd9caf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/eae2f14ab2efccdb7480fae7d42c4b0116ef8805"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23247.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23247"},{"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":"28ee1b746f493b7c62347d714f58fbf4f70df4f0"},{"fixed":"eae2f14ab2efccdb7480fae7d42c4b0116ef8805"},{"fixed":"46e5b0d7cf55821527adea471ffe52a5afbd9caf"},{"fixed":"165573e41f2f66ef98940cf65f838b2cb575d9d1"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0"},{"last_affected":"443fac9f2618b93cbc5ab068dc594530236b3a23"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23247.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.11.0"},{"fixed":"6.18.17"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23247.json"}}],"schema_version":"1.7.5"}