CVE-2026-63969
Received Received - Intake

Infinite Loop in Linux Kernel IPv6 Routing

Publication date: 2026-07-19

Last updated on: 2026-07-19

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: fix possible infinite loop in rt6_fill_node() Sashiko reported this issue [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(&rt->fib6_siblings) without waiting for RCU readers; rt->fib6_siblings.next then still points into the old ring and this softirq-side walker never reaches &rt->fib6_siblings, causing a CPU stall. fib6_del_route() always WRITE_ONCE()s rt->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

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-07-19
Last Modified
2026-07-19
Generated
2026-07-20
AI Q&A
2026-07-19
EPSS Evaluated
N/A
NVD
CVE-2026-63969
EUVD
EUVD-2026-45742

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This is a Linux kernel vulnerability where a possible infinite loop occurs in the IPv6 routing table handling function rt6_fill_node(). The issue arises when writers modify the routing table while readers are traversing it, leading to a CPU stall due to improper synchronization.

Detection Guidance

This vulnerability is specific to the Linux kernel's IPv6 routing implementation and may cause CPU stalls due to an infinite loop in rt6_fill_node(). Detection requires checking kernel logs for CPU stall warnings or system hangs related to IPv6 routing. Monitor for system unresponsiveness or watchdog timeouts.

Impact Analysis

This vulnerability could cause system hangs or crashes on Linux systems using IPv6 networking. It may lead to denial-of-service conditions where the affected system becomes unresponsive due to the infinite loop in the routing table processing.

Compliance Impact

This vulnerability does not directly affect compliance with standards like GDPR or HIPAA as it pertains to a Linux kernel networking issue causing potential CPU stalls. No evidence suggests data exposure or privacy violations.

Mitigation Strategies

Apply the latest kernel security updates provided by your Linux distribution. If no patch is available, consider disabling IPv6 temporarily as a workaround until the fix is applied. Restart services or reboot the system after applying updates.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-63969. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart