CVE-2026-31752 bridge: br_nd_send: validate ND option lengths
A malformed ND option in the Linux kernel bridge module can cause a denial of service by triggering an out-of-bounds read or parser error.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-31752?
CVE-2026-31752 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
bridge: br_nd_send: validate ND option lengths
br_nd_send() 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.
Which versions are affected by CVE-2026-31752?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31752?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-31752 being exploited?
There is no known exploitation of CVE-2026-31752 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-31752, DEBIAN-CVE-2026-31752, GHSA-32hh-f8j3-mw5q, ROOT-OS-DEBIAN-11-CVE-2026-31752, ROOT-OS-UBUNTU-2204-CVE-2026-31752, ROOT-OS-UBUNTU-2404-CVE-2026-31752 and 1 more.