{"id":"CVE-2026-43040","title":"net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak","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":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < 1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c","Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < 2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648","Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < 11d7fe97421cfc81549940c20ed5ac9472d6db05","Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < 7f56d87e527bb5a13c3e8b0d5840cb6332822f6d","Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < 4f810c686fde509d1cdaa706322d9d2531f8f1a4","Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < b485eef3d97b7aae55ce669b6de555ec81f3d21c","Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < ef3645606e4a635d5062a492f22b7f490852ee67","Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < ae05340ccaa9d347fe85415609e075545bec589f","Linux 2.6.24"],"published":"2026-05-01","updated":"2026-09-08","sourceUpdated":"2026-09-08T08:48:41.660Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43040","references":[{"url":"https://git.kernel.org/stable/c/1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c"},{"url":"https://git.kernel.org/stable/c/2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648"},{"url":"https://git.kernel.org/stable/c/11d7fe97421cfc81549940c20ed5ac9472d6db05"},{"url":"https://git.kernel.org/stable/c/7f56d87e527bb5a13c3e8b0d5840cb6332822f6d"},{"url":"https://git.kernel.org/stable/c/4f810c686fde509d1cdaa706322d9d2531f8f1a4"},{"url":"https://git.kernel.org/stable/c/b485eef3d97b7aae55ce669b6de555ec81f3d21c"},{"url":"https://git.kernel.org/stable/c/ef3645606e4a635d5062a492f22b7f490852ee67"},{"url":"https://git.kernel.org/stable/c/ae05340ccaa9d347fe85415609e075545bec589f"}],"tags":["cve.org"],"epss":0.00122,"epssPercentile":0.02316,"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 >= 31910575a9de61e78065e93846e8e7a4894a18bf < 1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c`\n- `Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < 2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b648`\n- `Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < 11d7fe97421cfc81549940c20ed5ac9472d6db05`\n- `Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < 7f56d87e527bb5a13c3e8b0d5840cb6332822f6d`\n- `Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < 4f810c686fde509d1cdaa706322d9d2531f8f1a4`\n- `Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < b485eef3d97b7aae55ce669b6de555ec81f3d21c`\n- `Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < ef3645606e4a635d5062a492f22b7f490852ee67`\n- `Linux >= 31910575a9de61e78065e93846e8e7a4894a18bf < ae05340ccaa9d347fe85415609e075545bec589f`\n- `Linux 2.6.24`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}