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Vulnerability · Published Feb 14, 2026 · Assigned by Linux

CVE-2026-23124ipv6: annotate data-race in ndisc_router_discovery()

Medium 5.5

In plain English

A medium-severity race condition 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 1% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.1%top 98.9% 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: ipv6: annotate data-race in ndisc_router_discovery() syzbot found that ndisc_router_discovery() could read and write in6_dev->ra_mtu without holding a lock [1] This looks fine, IFLA_INET6_RA_MTU is best effort. Add READ_ONCE()/WRITE_ONCE() to document the race. Note that we might also reject illegal MTU values (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) in a future patch. [1] BUG: KCSAN: data-race in ndisc_router_discovery / ndisc_router_discovery read to 0xffff888119809c20 of 4 bytes by task 25817 on cpu 1: ndisc_router_discovery+0x151d/0x1c90 net/ipv6/ndisc.c:1558 ndisc_rcv+0x2ad/0x3d0 net/ipv6/ndisc.c:1841 icmpv6_rcv+0xe5a/0x12f0 net/ipv6/icmp.c:989 ip6_protocol_deliver_rcu+0xb2a/0x10d0 net/ipv6/ip6_input.c:438 ip6_input_finish+0xf0/0x1d0 net/ipv6/ip6_input.c:489 NF_HOOK include/linux/netfilter.h:318 [inline] ip6_input+0x5e/0x140 net/ipv6/ip6_input.c:500 ip6_mc_input+0x27c/0x470 net/ipv6/ip6_input.c:590 dst_input include/net/dst.h:474 [inline] ip6_rcv_finish+0x336/0x340 net/ipv6/ip6_input.c:79 ... write to 0xffff888119809c20 of 4 bytes by task 25816 on cpu 0: ndisc_router_discovery+0x155a/0x1c90 net/ipv6/ndisc.c:1559 ndisc_rcv+0x2ad/0x3d0 net/ipv6/ndisc.c:1841 icmpv6_rcv+0xe5a/0x12f0 net/ipv6/icmp.c:989 ip6_protocol_deliver_rcu+0xb2a/0x10d0 net/ipv6/ip6_input.c:438 ip6_input_finish+0xf0/0x1d0 net/ipv6/ip6_input.c:489 NF_HOOK include/linux/netfilter.h:318 [inline] ip6_input+0x5e/0x140 net/ipv6/ip6_input.c:500 ip6_mc_input+0x27c/0x470 net/ipv6/ip6_input.c:590 dst_input include/net/dst.h:474 [inline] ip6_rcv_finish+0x336/0x340 net/ipv6/ip6_input.c:79 ... value changed: 0x00000000 -> 0xe5400659

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.162-1DEBIAN-CVE-2026-23124
Debian:13linux6.12.69-1DEBIAN-CVE-2026-23124
Debian:14linux6.18.8-1DEBIAN-CVE-2026-23124
Ubuntu:22.04:LTSlinux5.15.0-176.186UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux6.8.0-117.117UBUNTU-CVE-2026-23124
Ubuntu:25.10linuxno fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-aws5.15.0-1105.112UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-aws6.8.0-1055.58UBUNTU-CVE-2026-23124
Ubuntu:25.10linux-awsno fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1057.60~22.04.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-azure5.15.0-1110.119UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-azure6.8.0-1056.62UBUNTU-CVE-2026-23124
Ubuntu:25.10linux-azureno fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-azure-6.176.17.0-1021.21~24.04.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1059.65~22.04.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1114.123UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1058.65UBUNTU-CVE-2026-23124
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1058.65~22.04.1UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-gcp5.15.0-1105.114UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-gcp6.8.0-1058.61UBUNTU-CVE-2026-23124
Ubuntu:25.10linux-gcpno fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-gcp-6.176.17.0-1021.24~24.04.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1060.63~22.04.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-gke5.15.0-1101.107UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-gke6.8.0-1054.60UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1088.96UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1041.44UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-hwe-6.176.17.0-41.41~24.04.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-124.124~22.04.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-ibm5.15.0-1099.102UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-ibm6.8.0-1055.56UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1055.56~22.04.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1100.106UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-kvm5.15.0-1097.102UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-175.185UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-117.117.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-117.117.1~22.04.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1100.101UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1054.57UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-nvidia-6.176.17.0-1031.31UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1054.57~22.04.1UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1054.57.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1057.57UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1024.24UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1046.46UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-oem-6.176.17.0-1030.30UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-oracle5.15.0-1102.108UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-oracle6.8.0-1054.55UBUNTU-CVE-2026-23124
Ubuntu:25.10linux-oracleno fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-oracle-6.176.17.0-1019.19~24.04.3UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1054.55~22.04.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-raspi5.15.0-1099.102UBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-raspi6.8.0-1056.60UBUNTU-CVE-2026-23124
Ubuntu:25.10linux-raspino fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-23124
Ubuntu:25.10linux-realtimeno fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-23124
Ubuntu:25.10linux-riscvno fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-117.117~22.04.1UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-23124
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1032.33UBUNTU-CVE-2026-23124
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1070.74UBUNTU-CVE-2026-23124

Affected products (as reported)

VendorProductVersions
Linux Linux 49b99da2c9ce13ffcd93fe3a0f5670791c1d76f7 – before 4630897eb1a039b5d7b737b8dc9521d9d4b568b549b99da2c9ce13ffcd93fe3a0f5670791c1d76f7 – before 2619499169fb1c2ac4974b0f2d87767fb543582b49b99da2c9ce13ffcd93fe3a0f5670791c1d76f7 – before fad8f4ff7928f4d52a062ffdcffa484989c79c4749b99da2c9ce13ffcd93fe3a0f5670791c1d76f7 – before 2a2b9d25f801afecf2f83cacce98afa8fd73e3c949b99da2c9ce13ffcd93fe3a0f5670791c1d76f7 – before e3c1040252e598f7b4e33a42dc7c38519bc2242849b99da2c9ce13ffcd93fe3a0f5670791c1d76f7 – before 9a063f96d87efc3a6cc667f8de096a3d38d74bb5
Linux Linux 5.15

Weakness: CWE-362

References