CVE-2026-31738
VXLAN ND Option Length Validation Flaw in Linux Kernel
Publication date: 2026-05-01
Last updated on: 2026-05-01
Assigner: kernel.org
Description
Description
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
How can this vulnerability impact me? :
This vulnerability in the Linux kernel's vxlan_na_create function involves improper validation of Neighbor Discovery (ND) option lengths. A malformed option can cause the parser to read beyond the intended option span or use an incorrectly sized source link-layer address payload. This could potentially lead to unexpected behavior or memory corruption within the kernel's network processing.
Can you explain this vulnerability to me?
This vulnerability exists in the Linux kernel's vxlan component, specifically in the function vxlan_na_create. The function processes Neighbor Discovery (ND) options based on lengths provided by those options. However, if an option is malformed, the parser can either advance beyond the intended option span or use a source LLADDR option payload that is too short.
The fix involves validating the lengths of these options against the remaining Neighbor Solicitation (NS) option area before advancing the parser, and ensuring that the source LLADDR is only read when the option is large enough to contain a full Ethernet address.