{"id":"CVE-2020-7451","aliases":["EUVD-2020-28577","GHSA-vv76-2436-qvh9"],"status":"published","title":"In FreeBSD 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before...","description":"In FreeBSD 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, and 11.3-RELEASE before 11.3-RELEASE-p7, a TCP SYN-ACK or challenge TCP-ACK segment over IPv6 that is transmitted or retransmitted does not properly initialize the Traffic Class field disclosing one byte of kernel memory over the network.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.01169,"percentile":0.67654,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-200","CWE-908"],"published":"2020-04-28T19:11:42Z","modified":"2026-06-17T03:24:48Z","products":[{"vendor":"freebsd","product":"freebsd"}],"references":[{"url":"https://security.FreeBSD.org/advisories/FreeBSD-SA-20:04.tcp.asc","tags":["x_refsource_CONFIRM","x_transferred","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-7451"},{"url":"https://github.com/advisories/GHSA-vv76-2436-qvh9"}],"sources":{"cve":[{"id":"CVE-2020-7451","description":"In FreeBSD 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, and 11.3-RELEASE before 11.3-RELEASE-p7, a TCP SYN-ACK or challenge TCP-ACK segment over IPv6 that is transmitted or retransmitted does not properly initialize the Traffic Class field disclosing one byte of kernel memory over the network.","status":"published","published":"2020-04-28T19:11:42Z","modified":"2024-08-04T09:25:48.993Z","updated_at":"2026-11-02T14:35:58.787905Z"}],"euvd":[{"id":"EUVD-2020-28577","description":"In FreeBSD 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, and 11.3-RELEASE before 11.3-RELEASE-p7, a TCP SYN-ACK or challenge TCP-ACK segment over IPv6 that is transmitted or retransmitted does not properly initialize the Traffic Class field disclosing one byte of kernel memory over the network.","status":"published","published":"2020-04-28T19:11:42Z","modified":"2024-08-04T09:25:48Z","updated_at":"2026-11-03T03:08:00.054795Z"}],"ghsa":[{"id":"GHSA-vv76-2436-qvh9","title":"In FreeBSD 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before...","description":"In FreeBSD 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, and 11.3-RELEASE before 11.3-RELEASE-p7, a TCP SYN-ACK or challenge TCP-ACK segment over IPv6 that is transmitted or retransmitted does not properly initialize the Traffic Class field disclosing one byte of kernel memory over the network.","status":"published","published":"2022-05-24T17:16:47Z","modified":"2023-01-29T05:02:23Z","cwes":["CWE-200"],"updated_at":"2026-11-02T14:45:04.348172Z"}],"nvd":[{"id":"CVE-2020-7451","description":"In FreeBSD 12.1-STABLE before r358739, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r358740, and 11.3-RELEASE before 11.3-RELEASE-p7, a TCP SYN-ACK or challenge TCP-ACK segment over IPv6 that is transmitted or retransmitted does not properly initialize the Traffic Class field disclosing one byte of kernel memory over the network.","status":"published","published":"2020-04-28T20:15:12.797Z","modified":"2026-06-17T03:24:48.49Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:P/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-908"],"updated_at":"2026-11-02T14:05:59.718774Z"}]}}