In the Linux kernel, the following vulnerability has been resolved: ipv6: fix possible infinite loop in rt6_fill_node() Sashiko reported this issue… (CVE-2026-63969)
A vulnerability in the Linux kernel's IPv6 implementation could cause a possible infinite loop in the rt6_fill_node() function. This issue arises due to improper handling of the fib6_siblings list during route deletion, potentially leading to a CPU stall. The vulnerability has been resolved by applying a fix that ensures reliable detection of route detachment within the loop.
AI Analysis
Technical Summary
The Linux kernel contained a vulnerability in the IPv6 routing code where writers holding the tb6_lock could remove a route from the fib6_siblings list without waiting for RCU readers to complete. This caused the rt->fib6_siblings.next pointer to still reference the old list ring, resulting in the softirq-side walker failing to reach the list head and causing an infinite loop and CPU stall. The fix applies a check on rt->fib6_nsiblings, which is set to zero before list_del_rcu(), serving as a reliable signal to detach from the loop and prevent the infinite loop condition.
Potential Impact
This vulnerability could cause a CPU stall due to an infinite loop in the IPv6 routing code, potentially impacting system stability and availability. There is no indication of code execution or privilege escalation from the provided data.
Mitigation Recommendations
A fix has been applied to the Linux kernel to resolve this issue. Users should update to a kernel version that includes this patch. Since this is a kernel-level vulnerability, applying the official kernel update from the vendor or distribution is the recommended remediation.
In the Linux kernel, the following vulnerability has been resolved: ipv6: fix possible infinite loop in rt6_fill_node() Sashiko reported this issue… (CVE-2026-63969)
Description
A vulnerability in the Linux kernel's IPv6 implementation could cause a possible infinite loop in the rt6_fill_node() function. This issue arises due to improper handling of the fib6_siblings list during route deletion, potentially leading to a CPU stall. The vulnerability has been resolved by applying a fix that ensures reliable detection of route detachment within the loop.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel contained a vulnerability in the IPv6 routing code where writers holding the tb6_lock could remove a route from the fib6_siblings list without waiting for RCU readers to complete. This caused the rt->fib6_siblings.next pointer to still reference the old list ring, resulting in the softirq-side walker failing to reach the list head and causing an infinite loop and CPU stall. The fix applies a check on rt->fib6_nsiblings, which is set to zero before list_del_rcu(), serving as a reliable signal to detach from the loop and prevent the infinite loop condition.
Potential Impact
This vulnerability could cause a CPU stall due to an infinite loop in the IPv6 routing code, potentially impacting system stability and availability. There is no indication of code execution or privilege escalation from the provided data.
Mitigation Recommendations
A fix has been applied to the Linux kernel to resolve this issue. Users should update to a kernel version that includes this patch. Since this is a kernel-level vulnerability, applying the official kernel update from the vendor or distribution is the recommended remediation.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-wc3h-5qqj-xwhm
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-63969"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a5d27aa2a4a8d598912dbad
Added to database: 07/19/2026, 19:38:18 UTC
Last enriched: 07/19/2026, 20:00:16 UTC
Last updated: 07/20/2026, 17:49:32 UTC
Views: 10
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