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Vulnerability · Published Dec 16, 2025 · Assigned by Linux

CVE-2025-40363net: ipv6: fix field-spanning memcpy warning in AH output

Unrated

In plain English

A 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 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS )–Not rated
Exploit odds (30 days)0.2%top 88.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: net: ipv6: fix field-spanning memcpy warning in AH output Fix field-spanning memcpy warnings in ah6_output() and ah6_output_done() where extension headers are copied to/from IPv6 address fields, triggering fortify-string warnings about writes beyond the 16-byte address fields. memcpy: detected field-spanning write (size 40) of single field "&top_iph->saddr" at net/ipv6/ah6.c:439 (size 16) WARNING: CPU: 0 PID: 8838 at net/ipv6/ah6.c:439 ah6_output+0xe7e/0x14e0 net/ipv6/ah6.c:439 The warnings are false positives as the extension headers are intentionally placed after the IPv6 header in memory. Fix by properly copying addresses and extension headers separately, and introduce helper functions to avoid code duplication.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.159-1DEBIAN-CVE-2025-40363
Debian:13linux6.12.63-1DEBIAN-CVE-2025-40363
Debian:14linux6.17.8-1DEBIAN-CVE-2025-40363
Ubuntu:22.04:LTSlinux5.15.0-173.183UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux6.8.0-106.106UBUNTU-CVE-2025-40363
Ubuntu:25.10linux6.17.0-14.14UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-aws5.15.0-1103.110UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-aws6.8.0-1050.53UBUNTU-CVE-2025-40363
Ubuntu:25.10linux-aws6.17.0-1007.7UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-aws-6.176.17.0-1007.7~24.04.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1050.53~22.04.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-azure5.15.0-1109.118UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-azure6.8.0-1051.57UBUNTU-CVE-2025-40363
Ubuntu:25.10linux-azure6.17.0-1008.8UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1051.57~22.04.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1109.118.1UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1058.65UBUNTU-CVE-2025-40363
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1058.65~22.04.1UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-gcp5.15.0-1103.112UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-gcp6.8.0-1052.55UBUNTU-CVE-2025-40363
Ubuntu:25.10linux-gcp6.17.0-1007.7UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-gcp-6.176.17.0-1008.8~24.04.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1052.55~22.04.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-gke5.15.0-1099.105UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-gke6.8.0-1048.53UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1086.94UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1035.38UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-106.106~22.04.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-ibm5.15.0-1097.100UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-ibm6.8.0-1049.49UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1049.49~22.04.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1098.104UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-kvm5.15.0-1095.100UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-173.183UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-106.106.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-106.106.1~22.04.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1098.99UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1049.52UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-nvidia-6.176.17.0-1008.8UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1049.52~22.04.1UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1049.52.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1055.55UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1020.20UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1044.44UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-oem-6.176.17.0-1011.11UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-oracle5.15.0-1100.106UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-oracle6.8.0-1047.48UBUNTU-CVE-2025-40363
Ubuntu:25.10linux-oracle6.17.0-1007.7UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-oracle-6.176.17.0-1007.7~24.04.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1047.48~22.04.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-raspi5.15.0-1097.100UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-raspi6.8.0-1050.54UBUNTU-CVE-2025-40363
Ubuntu:25.10linux-raspi6.17.0-1008.8UBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-40363
Ubuntu:25.10linux-realtime6.17.0-1006.7UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-40363
Ubuntu:25.10linux-riscv6.17.0-14.14.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-106.106~22.04.1UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2025-40363
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1028.29UBUNTU-CVE-2025-40363
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1067.71UBUNTU-CVE-2025-40363

Affected products (as reported)

VendorProductVersions
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before 2da805a61ef5272a2773775ce14c3650adb842481da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before 9bf27de51bd6db5ff827780ec0eba55de230ba451da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before 0bf756ae1e69fec5e6332c37830488315d6d771b1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before 75b16b2755e12999ad850756ddfb88ad4bfc71861da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before f28dde240160f3c48a50d641d210ed6a3b9596ed1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before c14cf41094136691c92ef756872570645d61f4a11da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before b056f971bd72b373b7ae2025a8f3bd18f69653d31da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – before 2327a3d6f65ce2fe2634546dde4a25ef52296fec
Linux Linux 2.6.12

References