{"id":"CVE-2026-43383","title":"net/tcp-md5: Fix MAC comparison to be constant-time","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tcp-md5: Fix MAC comparison to be constant-time\n\nTo prevent timing attacks, MACs need to be compared in constant\ntime.  Use the appropriate helper function for this.","severity":"critical","cvss":9.4,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < 821c8751fdeecdeecabeb11704dd33439c9e4bbc","Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < ff44ec94d4fc8348600a69de0a8fa1102c23bce8","Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < 345a9530756528d7ca407663d659c3c40e75c3dd","Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < 5d305a95130a8d08b9545e47f1e18d29d59866cb","Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < 02669e2a4d207068edce7e8b5fafd85822018ce6","Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < ae3831b44f477de048287493e184fc3ff913b624","Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < b502e97e29d791ff7a8051f29a414535739be218","Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < 46d0d6f50dab706637f4c18a470aac20a21900d3","Linux 2.6.20"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-16T15:16:58.789451Z"},"published":"2026-05-08","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:20:40.656Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43383","references":[{"url":"https://git.kernel.org/stable/c/821c8751fdeecdeecabeb11704dd33439c9e4bbc"},{"url":"https://git.kernel.org/stable/c/ff44ec94d4fc8348600a69de0a8fa1102c23bce8"},{"url":"https://git.kernel.org/stable/c/345a9530756528d7ca407663d659c3c40e75c3dd"},{"url":"https://git.kernel.org/stable/c/5d305a95130a8d08b9545e47f1e18d29d59866cb"},{"url":"https://git.kernel.org/stable/c/02669e2a4d207068edce7e8b5fafd85822018ce6"},{"url":"https://git.kernel.org/stable/c/ae3831b44f477de048287493e184fc3ff913b624"},{"url":"https://git.kernel.org/stable/c/b502e97e29d791ff7a8051f29a414535739be218"},{"url":"https://git.kernel.org/stable/c/46d0d6f50dab706637f4c18a470aac20a21900d3"}],"tags":["cve.org"],"epss":0.00443,"epssPercentile":0.37053,"ingestedAt":"2026-10-16T17:24:46.694Z","slug":"CVE-2026-43383","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/tcp-md5: Fix MAC comparison to be constant-time\n\nTo prevent timing attacks, MACs need to be compared in constant\ntime.  Use the appropriate helper function for this.\n\n## Affected\n\n- `Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < 821c8751fdeecdeecabeb11704dd33439c9e4bbc`\n- `Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < ff44ec94d4fc8348600a69de0a8fa1102c23bce8`\n- `Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < 345a9530756528d7ca407663d659c3c40e75c3dd`\n- `Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < 5d305a95130a8d08b9545e47f1e18d29d59866cb`\n- `Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < 02669e2a4d207068edce7e8b5fafd85822018ce6`\n- `Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < ae3831b44f477de048287493e184fc3ff913b624`\n- `Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < b502e97e29d791ff7a8051f29a414535739be218`\n- `Linux >= cfb6eeb4c860592edd123fdea908d23c6ad1c7dc < 46d0d6f50dab706637f4c18a470aac20a21900d3`\n- `Linux 2.6.20`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":52,"depthScoreParts":{"impact":51.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}