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Vulnerability · Published Aug 22, 2026 · Assigned by Linux

CVE-2026-74657ipv4: Fix fib_nlmsg_size() for RTA_VIA nexthops

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 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS )–Not rated
Exploit odds (30 days)0.2%top 92.7% 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: ipv4: Fix fib_nlmsg_size() for RTA_VIA nexthops fib_nlmsg_size() still estimates nexthop space as if every gateway is encoded as an IPv4 RTA_GATEWAY attribute. IPv4 routes can also carry an IPv6 gateway, which fib_nexthop_info() dumps as RTA_VIA. As a result, route notifications can allocate an skb that is too small. fib_dump_info() then fails with -EMSGSIZE and rtmsg_fib() hits the WARN_ON() that marks such failures as a fib_nlmsg_size() bug. With panic_on_warn set, this becomes a kernel panic. Mirror the actual nexthop dump layout in fib_nlmsg_size(): account for IPv6 nexthop gateways dumped as RTA_VIA, for the no-header rtnexthop layout used inside RTA_MULTIPATH, and for RTA_FLOW only when it is actually present.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.187-1DEBIAN-CVE-2026-74657
Debian:13linux6.12.105-1DEBIAN-CVE-2026-74657
Debian:14linux7.1.9-1DEBIAN-CVE-2026-74657
Debian:12linux-6.126.12.107-1~deb12u1DEBIAN-CVE-2026-74657
Ubuntu:22.04:LTSlinux5.15.0-198.208UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinuxno fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux7.0.0-42.42UBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-aws5.15.0-1117.124UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-awsno fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-aws7.0.0-1016.17UBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-aws-6.8no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-aws-7.0no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-azure5.15.0-1123.132UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-azure-6.8no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-azure-7.0no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1122.131UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-azure-fde-6.8no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-azure-fde-7.0no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-gcp5.15.0-1118.128UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-gcpno fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-gcp7.0.0-1016.18UBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-gcp-6.8no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-gcp-7.0no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-gke5.15.0-1113.119UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1100.108UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-gkeopno fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-hwe-6.8no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-42.42~24.04.1UBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-ibm5.15.0-1111.115UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-ibmno fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-ibm7.0.0-1017.17UBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-ibm-6.8no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1112.118UBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-kvm5.15.0-1109.114UBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-195.205UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-lowlatencyno fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.8no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1112.113UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-nvidia-6.8no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-nvidia-7.0no fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-nvidia-bosno fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-nvidia-lowlatencyno fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1070.72UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-nvidia-tegrano fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1059.59UBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1017.17UBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-oracle5.15.0-1114.120UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-oracleno fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-oracle7.0.0-1015.16UBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-oracle-6.8no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-oracle-7.0no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-74657
Ubuntu:26.04:LTSlinux-riscv7.0.0-42.42.1UBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-riscv-6.8no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-42.42.1~24.04.1UBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-vmwareno fix listedUBUNTU-CVE-2026-74657
Ubuntu:24.04:LTSlinux-xilinxno fix listedUBUNTU-CVE-2026-74657
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1080.84UBUNTU-CVE-2026-74657

Affected products (as reported)

VendorProductVersions
Linux Linux d15662682db232da77136cd348f4c9df312ca6f9 – before 57195f0ab5cfbb5ee0864e5aff15ceb48f5a5e28d15662682db232da77136cd348f4c9df312ca6f9 – before 0f0ca602941d0a81ae9514943ca06c55159c6385d15662682db232da77136cd348f4c9df312ca6f9 – before 5307a53599fa762c06e475ee4a375252074fd324d15662682db232da77136cd348f4c9df312ca6f9 – before 7f80ad373ce4a7af5367ff273cea0f16e91387f3d15662682db232da77136cd348f4c9df312ca6f9 – before 4a5dfbae5179f6574695012a980476254df2d295d15662682db232da77136cd348f4c9df312ca6f9 – before a59edda6eda1252340354322d8ab318b2e9052fbd15662682db232da77136cd348f4c9df312ca6f9 – before 9b22f13524fa0de0d963bbd3002df6c28bae3395d15662682db232da77136cd348f4c9df312ca6f9 – before 4ff9548d84945d2cbf9e4c207288063a200ea397
Linux Linux 5.2

References