CVE-2026-31752

Analyzed Analyzed - Analysis Complete

Linux Kernel ND Option Length Validation Flaw

Publication date: 2026-05-01

Last updated on: 2026-05-07

Assigner: kernel.org

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.

CVSS Scores

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Meta Information

Published

2026-05-01

Last Modified

2026-05-07

Generated

2026-07-06

AI Q&A

2026-05-01

EPSS Evaluated

2026-07-05

NVD

CVE-2026-31752

EUVD

EUVD-2026-26565

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	From 5.11 (inc) to 5.15.203 (exc)
linux	linux_kernel	From 6.13 (inc) to 6.18.22 (exc)
linux	linux_kernel	From 5.16 (inc) to 6.1.168 (exc)
linux	linux_kernel	From 6.19 (inc) to 6.19.12 (exc)
linux	linux_kernel	From 6.7 (inc) to 6.12.81 (exc)
linux	linux_kernel	From 6.2 (inc) to 6.6.134 (exc)
linux	linux_kernel	From 4.15 (inc) to 5.10.253 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability exists in the Linux kernel's bridge component, specifically in the br_nd_send() function which processes Neighbor Discovery (ND) options.

The function walks through ND options based on lengths provided by the options themselves. However, if an option is malformed, it can cause the parser to read beyond the intended option boundary or incorrectly handle a source Link-Layer Address (LLADDR) option that is too short.

The fix involves validating the lengths of options against the remaining Neighbor Solicitation (NS) option area before advancing the parser, and only reading the source LLADDR when the option is large enough to contain a full Ethernet address.

Impact Analysis

This vulnerability in the Linux kernel's bridge component involves improper validation of Neighbor Discovery (ND) option lengths. A malformed ND option can cause the parser to read beyond the intended option boundaries or process an incorrectly sized source link-layer address. This could potentially lead to unexpected behavior in network packet processing, which might be exploited to cause denial of service or other network-related issues.

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