Infinite loop in Linux kernel - CVE-2026-63968
Published: July 20, 2026
Vulnerability identifier: #VU138688
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-63968
CWE-ID: CWE-835
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local attacker to cause a denial of service.
The vulnerability exists due to an infinite loop in fib6_select_path() when walking IPv6 route sibling entries during softirq-side processing. A local attacker can trigger route processing to cause a denial of service.
The issue occurs because a detached sibling entry may still point into an old ring, preventing the walker from reaching its termination condition.
How to mitigate CVE-2026-63968
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/0f7b73c3452635de83b8711b31abdda8e49aad7b
- https://git.kernel.org/stable/c/3948a7d92f7678e89e1776bb2d169afcad63b1ae
- https://git.kernel.org/stable/c/9b9d5bd6e3d4c9cecab5407604b690684b2532d2
- https://git.kernel.org/stable/c/9c7da87c2dc860bb17ca1ece942495d28b1ce3b9
- https://git.kernel.org/stable/c/ab9a10969a907b472a0196d999c08ff7144172e3
- https://git.kernel.org/stable/c/c87cd3cb309634bc8f50a54e2079424f219ac21f