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Vulnerability · Published May 1, 2026 · Assigned by Linux

CVE-2026-43040net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak

High 7.1

In plain English

A high-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)7.1High
Exploit odds (30 days)0.1%top 97.4% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: net: ipv6: ndisc: fix ndisc_ra_useropt to initialize nduseropt_padX fields to zero to prevent an info-leak When processing Router Advertisements with user options the kernel builds an RTM_NEWNDUSEROPT netlink message. The nduseroptmsg struct has three padding fields that are never zeroed and can leak kernel data The fix is simple, just zeroes the padding fields.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.170-1DEBIAN-CVE-2026-43040
Debian:13linux6.12.85-1DEBIAN-CVE-2026-43040
Debian:14linux6.19.12-1DEBIAN-CVE-2026-43040
Ubuntu:22.04:LTSlinux5.15.0-186.196UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux6.8.0-136.136UBUNTU-CVE-2026-43040
Ubuntu:25.10linuxno fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-aws5.15.0-1112.119UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-aws6.8.0-1061.64UBUNTU-CVE-2026-43040
Ubuntu:25.10linux-awsno fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1061.64~22.04.1UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-azure5.15.0-1117.126UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-azure6.8.0-1063.71UBUNTU-CVE-2026-43040
Ubuntu:25.10linux-azureno fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1063.71~22.04.1UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1117.126UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1062.69UBUNTU-CVE-2026-43040
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1062.69~22.04.1UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-gcp5.15.0-1112.122UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-gcp6.8.0-1064.72UBUNTU-CVE-2026-43040
Ubuntu:25.10linux-gcpno fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1064.72~22.04.1UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-gke5.15.0-1108.114UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-gke6.8.0-1059.67UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1095.103UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1046.50UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-136.136~22.04.1UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-ibm5.15.0-1106.110UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-ibm6.8.0-1061.62UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1061.62~22.04.1UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1107.113UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-kvm5.15.0-1104.109UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-184.194UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-136.136.2UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-136.136.2~22.04.1UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1107.108UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1059.62UBUNTU-CVE-2026-43040
Ubuntu:26.04:LTSlinux-nvidia7.0.0-1006.6UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1059.62~22.04.1UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1059.62.1UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1064.66UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1030.31UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1053.53UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-oracle5.15.0-1109.115UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-oracle6.8.0-1058.61UBUNTU-CVE-2026-43040
Ubuntu:25.10linux-oracleno fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1058.61~22.04.1UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-raspi5.15.0-1106.109UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-raspi6.8.0-1061.65UBUNTU-CVE-2026-43040
Ubuntu:25.10linux-raspino fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-43040
Ubuntu:25.10linux-realtimeno fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-43040
Ubuntu:25.10linux-riscvno fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-136.136~22.04.3UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-vmware6.8.0-1008.8UBUNTU-CVE-2026-43040
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1033.34UBUNTU-CVE-2026-43040
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1075.79UBUNTU-CVE-2026-43040

Affected products (as reported)

VendorProductVersions
Linux Linux 31910575a9de61e78065e93846e8e7a4894a18bf – before 1da9023f6b071a38e5430ffbce4b70b2b1ac4f9c31910575a9de61e78065e93846e8e7a4894a18bf – before 2fe4d0ba690a69ad6ae9f7ab9bdc96e02610b64831910575a9de61e78065e93846e8e7a4894a18bf – before 11d7fe97421cfc81549940c20ed5ac9472d6db0531910575a9de61e78065e93846e8e7a4894a18bf – before 7f56d87e527bb5a13c3e8b0d5840cb6332822f6d31910575a9de61e78065e93846e8e7a4894a18bf – before 4f810c686fde509d1cdaa706322d9d2531f8f1a431910575a9de61e78065e93846e8e7a4894a18bf – before b485eef3d97b7aae55ce669b6de555ec81f3d21c31910575a9de61e78065e93846e8e7a4894a18bf – before ef3645606e4a635d5062a492f22b7f490852ee6731910575a9de61e78065e93846e8e7a4894a18bf – before ae05340ccaa9d347fe85415609e075545bec589f
Linux Linux 2.6.24

References