CVE-2026-31738: vxlan: validate ND option lengths in vxlan_na_create
In the Linux kernel, the following vulnerability has been resolved:
vxlan: validate ND option lengths in vxlannacreate
vxlannacreate() walks ND options according to option-provided lengths. A malformed option can make the parser advance beyond the computed option span or use a too-short source LLADDR option payload.
Validate option lengths against the remaining NS option area before advancing, and only read source LLADDR when the option is large enough for an Ethernet address.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.113-1Fixed in 7.2.12-1Fixed in 7.2.13-1
Event History
Frequently Asked Questions
What access does an attacker need to exploit this issue?
The vulnerability has a local attack vector and requires low privileges. No user interaction is required.
What is the impact of successful exploitation?
The reported impact is limited to availability. The vulnerability can cause a denial of service, with no reported confidentiality or integrity impact.
What traffic or component is involved?
The issue is in the Linux kernel VXLAN handling path when vxlan_na_create() parses Neighbor Discovery options, including source link-layer address options. Exploitation involves malformed ND option lengths.