{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23247","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-01-13T15:37:45.989Z","datePublished":"2026-03-18T10:05:09.353Z","dateUpdated":"2026-11-05T21:33:32.445Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-30T12:23:52.715Z"},"descriptions":[{"lang":"en","value":"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."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/secure_seq.h","include/net/tcp.h","net/core/secure_seq.c","net/ipv4/syncookies.c","net/ipv4/tcp_input.c","net/ipv4/tcp_ipv4.c","net/ipv6/syncookies.c","net/ipv6/tcp_ipv6.c"],"versions":[{"version":"28ee1b746f493b7c62347d714f58fbf4f70df4f0","lessThan":"025f532d8c5cfac77845e50daab7f478b360f2ac","status":"affected","versionType":"git"},{"version":"28ee1b746f493b7c62347d714f58fbf4f70df4f0","lessThan":"e873e8c16b2fb743a381a9e59c108e63512301ec","status":"affected","versionType":"git"},{"version":"28ee1b746f493b7c62347d714f58fbf4f70df4f0","lessThan":"5da5662181ef8a251e3ba564903002c2e87de452","status":"affected","versionType":"git"},{"version":"28ee1b746f493b7c62347d714f58fbf4f70df4f0","lessThan":"eae2f14ab2efccdb7480fae7d42c4b0116ef8805","status":"affected","versionType":"git"},{"version":"28ee1b746f493b7c62347d714f58fbf4f70df4f0","lessThan":"46e5b0d7cf55821527adea471ffe52a5afbd9caf","status":"affected","versionType":"git"},{"version":"28ee1b746f493b7c62347d714f58fbf4f70df4f0","lessThan":"165573e41f2f66ef98940cf65f838b2cb575d9d1","status":"affected","versionType":"git"},{"version":"443fac9f2618b93cbc5ab068dc594530236b3a23","status":"affected","versionType":"git"},{"version":"4.10.14","lessThan":"4.11","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/secure_seq.h","include/net/tcp.h","net/core/secure_seq.c","net/ipv4/syncookies.c","net/ipv4/tcp_input.c","net/ipv4/tcp_ipv4.c","net/ipv6/syncookies.c","net/ipv6/tcp_ipv6.c"],"versions":[{"version":"4.11","status":"affected"},{"version":"0","lessThan":"4.11","status":"unaffected","versionType":"semver"},{"version":"6.1.191","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.160","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.94","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.17","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"6.19.7","lessThanOrEqual":"6.19.*","status":"unaffected","versionType":"semver"},{"version":"7.0","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.12.94"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.18.17"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.19.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"7.0"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.10.14"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/025f532d8c5cfac77845e50daab7f478b360f2ac"},{"url":"https://git.kernel.org/stable/c/e873e8c16b2fb743a381a9e59c108e63512301ec"},{"url":"https://git.kernel.org/stable/c/5da5662181ef8a251e3ba564903002c2e87de452"},{"url":"https://git.kernel.org/stable/c/eae2f14ab2efccdb7480fae7d42c4b0116ef8805"},{"url":"https://git.kernel.org/stable/c/46e5b0d7cf55821527adea471ffe52a5afbd9caf"},{"url":"https://git.kernel.org/stable/c/165573e41f2f66ef98940cf65f838b2cb575d9d1"}],"title":"tcp: secure_seq: add back ports to TS offset","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-23247","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-11-05T21:23:07.659265Z"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-11-05T21:33:32.445Z"}}]}}