{"id":"CVE-2026-43040","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak\n\nWhen processing Router Advertisements with user options the …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak\n\nWhen processing Router Advertisements with user options the …","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","cwe":["CWE-909"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 2.6.24, < 5.10.253","linux_kernel >= 5.11, < 5.15.203","linux_kernel >= 5.16, < 6.1.168","linux_kernel >= 6.2, < 6.6.134","linux_kernel >= 6.7, < 6.12.81","linux_kernel >= 6.13, < 6.18.22","linux_kernel >= 6.19, < 6.19.12","linux_kernel = 7.0"],"patched":["linux_kernel 6.19.12"],"published":"2026-05-01","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:19:29.050","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-43040","references":[{"url":"https://git.kernel.org/stable/c/11d7fe97421cfc81549940c20ed5ac9472d6db05","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4f810c686fde509d1cdaa706322d9d2531f8f1a4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7f56d87e527bb5a13c3e8b0d5840cb6332822f6d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ae05340ccaa9d347fe85415609e075545bec589f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b485eef3d97b7aae55ce669b6de555ec81f3d21c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ef3645606e4a635d5062a492f22b7f490852ee67","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-082556.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00129,"epssPercentile":0.02508,"ingestedAt":"2026-09-08T15:33:26.989Z","slug":"CVE-2026-43040","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak\n\nWhen processing Router Advertisements with user options the kernel\nbuilds an RTM_NEWNDUSEROPT netlink message. The nduseroptmsg struct\nhas three padding fields that are never zeroed and can leak kernel data\n\nThe fix is simple, just zeroes the padding fields.\n\n## Affected\n\n- `linux_kernel >= 2.6.24, < 5.10.253`\n- `linux_kernel >= 5.11, < 5.15.203`\n- `linux_kernel >= 5.16, < 6.1.168`\n- `linux_kernel >= 6.2, < 6.6.134`\n- `linux_kernel >= 6.7, < 6.12.81`\n- `linux_kernel >= 6.13, < 6.18.22`\n- `linux_kernel >= 6.19, < 6.19.12`\n- `linux_kernel = 7.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.19.12`","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":221759,"id":"CVE-2026-43040","ts":1792035359787,"field":"cvss","old":null,"new":"7.1"},{"seq":221758,"id":"CVE-2026-43040","ts":1792035359787,"field":"severity","old":"none","new":"high"}]}