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Vulnerability · Published Jul 19, 2026 · Assigned by Linux

CVE-2026-63968ipv6: fix possible infinite loop in fib6_select_path()

High 7.5

In plain English

A high-severity infinite loop 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 0.7% (higher than 52% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.7%top 48.1% 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: fix possible infinite loop in fib6_select_path() Found while auditing the same pattern Sashiko reported in rt6_fill_node() [1]. Apply the same fix as commit f8d8ce1b515a ("ipv6: fix possible infinite loop in fib6_info_uses_dev()"). Writers holding tb6_lock can list_del_rcu(&first->fib6_siblings) without waiting for RCU readers; first->fib6_siblings.next then still points into the old ring and this softirq-side walker never reaches &first->fib6_siblings as its terminator. fib6_purge_rt() always WRITE_ONCE()s first->fib6_nsiblings to 0 before list_del_rcu(), so an inside-loop check is a reliable detach signal. [1] https://sashiko.dev/#/patchset/20260526020227.4857-1-jiayuan.chen%40linux.dev

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.176-1DEBIAN-CVE-2026-63968
Debian:13linux6.12.94-1DEBIAN-CVE-2026-63968
Debian:14linux7.0.12-1DEBIAN-CVE-2026-63968
Ubuntu:24.04:LTSlinux6.8.0-146.146UBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux7.0.0-28.28UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-aws6.8.0-1066.69UBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-aws7.0.0-1009.9UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1066.69~22.04.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-azure6.8.0-1070.78UBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-azure7.0.0-1010.10UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1070.78~22.04.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-azure-7.07.0.0-1014.14~24.04.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1068.75UBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-azure-fde7.0.0-1009.9UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1068.75~22.04.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-azure-fde-7.07.0.0-1013.13~24.04.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-gcp6.8.0-1070.78UBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-gcp7.0.0-1008.8UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1070.78~22.04.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-gcp-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-gke6.8.0-1065.73UBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-gke7.0.0-1003.4UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1051.55UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-hwe-6.8no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-28.28~24.04.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-ibm6.8.0-1066.67UBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-ibm7.0.0-1010.10UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1066.67~22.04.1UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-146.146.1UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-146.146.1~22.04.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1064.67UBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-nvidia7.0.0-1016.16UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1064.67~22.04.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-nvidia-7.07.0.0-1016.16~24.04.1UBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-nvidia-bos7.0.0-2016.16UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1064.67.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1036.39UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1009.9UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-oracle6.8.0-1063.66UBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-oracle7.0.0-1008.8UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-oracle-6.8no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-oracle-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-raspi7.0.0-1015.15UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-realtime7.0.0-28.28.1UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-63968
Ubuntu:26.04:LTSlinux-riscv7.0.0-28.28.1UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-146.146~22.04.1UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-28.28.1~24.04.3UBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-63968
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-vmware6.8.0-1008.8UBUNTU-CVE-2026-63968
Ubuntu:24.04:LTSlinux-xilinxno fix listedUBUNTU-CVE-2026-63968

Affected products (as reported)

VendorProductVersions
Linux Linux d0ec61c9f3583b76aebdbb271f5c0d3fcccd48b2 – before 3948a7d92f7678e89e1776bb2d169afcad63b1ae52da02521ede55fb86546c3fffd9377b3261b91f – before c87cd3cb309634bc8f50a54e2079424f219ac21f34a949e7a0869dfa31a40416d2a56973fae1807b – before 0f7b73c3452635de83b8711b31abdda8e49aad7bd9ccb18f83ea2bb654289b6ecf014fd267cc988b – before ab9a10969a907b472a0196d999c08ff7144172e3d9ccb18f83ea2bb654289b6ecf014fd267cc988b – before 9b9d5bd6e3d4c9cecab5407604b690684b2532d2d9ccb18f83ea2bb654289b6ecf014fd267cc988b – before 9c7da87c2dc860bb17ca1ece942495d28b1ce3b911edcd026012ac18acee0f1514db3ed1b160fc6f6.1.128 – before 6.1.176
Linux Linux 6.13

Weakness: CWE-835 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References