{"id":"CVE-2026-31685","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ip6t_eui64: reject invalid MAC header for all packets\n\n`eui64_mt6()` derives a modified EUI-64 from the Ethernet source address\nand compares it with the low …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ip6t_eui64: reject invalid MAC header for all packets\n\n`eui64_mt6()` derives a modified EUI-64 from the Ethernet source address\nand compares it with the low …","severity":"critical","cvss":9.4,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 2.6.12.1, < 6.6.136","linux_kernel >= 6.7, < 6.12.83","linux_kernel >= 6.13, < 6.18.24","linux_kernel >= 6.19, < 6.19.14","linux_kernel = 2.6.12","linux_kernel = 7.0"],"patched":["linux_kernel 6.19.14"],"published":"2026-04-25","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:19:17.423","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-31685","references":[{"url":"https://git.kernel.org/stable/c/288138418bef956f8b295751a4536c60f0e89f4a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/309ae3e9a51a69699ca94eac5fac5688fa562d55","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4d75bc2cd093bf5803edf512c099bfb220fd6459","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7d6a57411caf54df025860c9b1a82cd42d57a562","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/807d6ee15804df6f01a35c910f09612e858739a6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9eda5478746ef7dc0e4e537b5a5e4b0ca1027091","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d5603591373441fecf9951833d6d873e09320f08","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fdce0b3590f724540795b874b4c8850c90e6b0a8","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00337,"epssPercentile":0.25488,"ingestedAt":"2026-10-15T03:30:12.864Z","slug":"CVE-2026-31685","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ip6t_eui64: reject invalid MAC header for all packets\n\n`eui64_mt6()` derives a modified EUI-64 from the Ethernet source address\nand compares it with the low 64 bits of the IPv6 source address.\n\nThe existing guard only rejects an invalid MAC header when\n`par->fragoff != 0`. For packets with `par->fragoff == 0`, `eui64_mt6()`\ncan still reach `eth_hdr(skb)` even when the MAC header is not valid.\n\nFix this by removing the `par->fragoff != 0` condition so that packets\nwith an invalid MAC header are rejected before accessing `eth_hdr(skb)`.\n\n## Affected\n\n- `linux_kernel >= 2.6.12.1, < 6.6.136`\n- `linux_kernel >= 6.7, < 6.12.83`\n- `linux_kernel >= 6.13, < 6.18.24`\n- `linux_kernel >= 6.19, < 6.19.14`\n- `linux_kernel = 2.6.12`\n- `linux_kernel = 7.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.19.14`","depth":"midnight","depthScore":52,"depthScoreParts":{"impact":51.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}