CVE-2026-46037

Analyzed Analyzed - Analysis Complete

ICMP Reply Validation Bypass in Linux Kernel

Publication date: 2026-05-27

Last updated on: 2026-06-16

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: ipv4: icmp: validate reply type before using icmp_pointers Extended echo replies use ICMP_EXT_ECHOREPLY as the outbound reply type. That value is outside the range covered by icmp_pointers[], which only describes the traditional ICMP types up to NR_ICMP_TYPES. Avoid consulting icmp_pointers[] for reply types outside that range, and use array_index_nospec() for the remaining in-range lookup. Normal ICMP replies keep their existing behavior unchanged.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-05-27

Last Modified

2026-06-16

Generated

2026-07-06

AI Q&A

2026-05-27

EPSS Evaluated

2026-07-05

NVD

CVE-2026-46037

EUVD

EUVD-2026-32418

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	From 6.7 (inc) to 6.12.86 (exc)
linux	linux_kernel	From 5.13 (inc) to 5.15.209 (exc)
linux	linux_kernel	From 5.16 (inc) to 6.1.175 (exc)
linux	linux_kernel	From 6.2 (inc) to 6.6.140 (exc)
linux	linux_kernel	From 6.13 (inc) to 6.18.27 (exc)
linux	linux_kernel	From 6.19 (inc) to 7.0.4 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability exists in the Linux kernel's handling of ICMP (Internet Control Message Protocol) messages. Specifically, it involves the validation of the reply type before using the icmp_pointers array. Extended echo replies use a reply type called ICMP_EXT_ECHOREPLY, which is outside the range covered by the icmp_pointers array that only handles traditional ICMP types. The vulnerability arises because the kernel might consult icmp_pointers[] for reply types outside its valid range, potentially leading to incorrect behavior or memory issues.

The fix involves avoiding the use of icmp_pointers[] for reply types outside the valid range and using a safer method (array_index_nospec()) for in-range lookups, ensuring normal ICMP replies behave as before.

Impact Analysis

If exploited, this vulnerability could cause the Linux kernel to behave incorrectly when processing certain ICMP extended echo replies. This might lead to unexpected kernel behavior, including potential memory safety issues or crashes, which could be leveraged by an attacker to disrupt system stability or cause denial of service.

Hi! I’m here to help you understand CVE-2026-46037. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70