{"id":"CVE-2023-1206","title":"A hash collision flaw was found in the IPv6 connection lookup table in the Linux kernel’s IPv6 functionality when a user makes a new kind of SYN flood attack","summary":"A hash collision flaw was found in the IPv6 connection lookup table in the Linux kernel’s IPv6 functionality when a user makes a new kind of SYN flood attack. A user located in the local network or with a high bandwidth connection can in…","severity":"medium","cvss":5.7,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-400","CWE-400"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel < 6.5","enterprise_linux = 8.0","enterprise_linux = 9.0","fedora = 38"],"patched":["linux_kernel 6.5"],"published":"2023-06-30","updated":"2026-10-14","sourceUpdated":"2026-10-14T21:17:14.790","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2023-1206","references":[{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2175903","label":"secalert@redhat.com"},{"url":"https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html","label":"secalert@redhat.com"},{"url":"https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html","label":"secalert@redhat.com"},{"url":"https://security.netapp.com/advisory/ntap-20230929-0006/","label":"secalert@redhat.com"},{"url":"https://www.debian.org/security/2023/dsa-5480","label":"secalert@redhat.com"},{"url":"https://www.debian.org/security/2023/dsa-5492","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2175903","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20230929-0006/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2023/dsa-5480","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2023/dsa-5492","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-769027.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-794697.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-806742.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","exploit-available"],"epss":0.00549,"epssPercentile":0.44601,"exploits":{"github":1,"githubRepos":["https://github.com/SpiralBL0CK/CVE-2023-1206-CVE-2025-40040-CVE-2024-49882"],"checkedAt":"2026-10-14T21:57:39.234Z"},"exploitAvailable":true,"ingestedAt":"2026-10-14T21:57:04.735Z","slug":"CVE-2023-1206","body":"## Overview\n\nA hash collision flaw was found in the IPv6 connection lookup table in the Linux kernel’s IPv6 functionality when a user makes a new kind of SYN flood attack. A user located in the local network or with a high bandwidth connection can increase the CPU usage of the server that accepts IPV6 connections up to 95%.\n\n## Affected\n\n- `linux_kernel < 6.5`\n- `enterprise_linux = 8.0`\n- `enterprise_linux = 9.0`\n- `fedora = 38`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.5`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":31.4,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[]}