---
id: CVE-2026-43491
title: 'net: qrtr: ns: Limit the maximum server registration per node'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: qrtr: ns: Limit the maximum server registration per node

  Current code does no bound checking on the number of servers added per
  node. A malicious client can flood…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd <
    b48fc702b20233b809f01053232c3cd5083c97b4
  - >-
    Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd <
    991c431077b19176d3fe3bb54054c063776a8cdc
  - >-
    Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd <
    94914731ca0b99899dceadd80d2df00584a688ca
  - >-
    Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd <
    e6f6cd501fb54060940a6eb3f4103eeb5e426ae7
  - >-
    Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd <
    3efaad55cad1ded429e3a873bfece389058a526b
  - >-
    Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd <
    35fb4a0c077c5d1049c2628b769e0a1b1e65df0d
  - >-
    Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd <
    868202aa2adae427060a42d5bd663b4d782ec02c
  - >-
    Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd <
    d5ee2ff98322337951c56398e79d51815acbf955
  - Linux 5.7
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T15:41:13.574482Z'
published: '2026-05-19'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T15:42:57.704Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-43491'
references:
  - url: 'https://git.kernel.org/stable/c/b48fc702b20233b809f01053232c3cd5083c97b4'
  - url: 'https://git.kernel.org/stable/c/991c431077b19176d3fe3bb54054c063776a8cdc'
  - url: 'https://git.kernel.org/stable/c/94914731ca0b99899dceadd80d2df00584a688ca'
  - url: 'https://git.kernel.org/stable/c/e6f6cd501fb54060940a6eb3f4103eeb5e426ae7'
  - url: 'https://git.kernel.org/stable/c/3efaad55cad1ded429e3a873bfece389058a526b'
  - url: 'https://git.kernel.org/stable/c/35fb4a0c077c5d1049c2628b769e0a1b1e65df0d'
  - url: 'https://git.kernel.org/stable/c/868202aa2adae427060a42d5bd663b4d782ec02c'
  - url: 'https://git.kernel.org/stable/c/d5ee2ff98322337951c56398e79d51815acbf955'
tags:
  - cve.org
epss: 0.00149
epssPercentile: 0.04112
ingestedAt: '2026-11-06T15:54:03.890Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

net: qrtr: ns: Limit the maximum server registration per node

Current code does no bound checking on the number of servers added per
node. A malicious client can flood NEW_SERVER messages and exhaust memory.

Fix this issue by limiting the maximum number of server registrations to
256 per node. If the NEW_SERVER message is received for an old port, then
don't restrict it as it will get replaced. While at it, also rate limit
the error messages in the failure path of qrtr_ns_worker().

Note that the limit of 256 is chosen based on the current platform
requirements. If requirement changes in the future, this limit can be
increased.

## Affected

- `Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd < b48fc702b20233b809f01053232c3cd5083c97b4`
- `Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd < 991c431077b19176d3fe3bb54054c063776a8cdc`
- `Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd < 94914731ca0b99899dceadd80d2df00584a688ca`
- `Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd < e6f6cd501fb54060940a6eb3f4103eeb5e426ae7`
- `Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd < 3efaad55cad1ded429e3a873bfece389058a526b`
- `Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd < 35fb4a0c077c5d1049c2628b769e0a1b1e65df0d`
- `Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd < 868202aa2adae427060a42d5bd663b4d782ec02c`
- `Linux >= 0c2204a4ad710d95d348ea006f14ba926e842ffd < d5ee2ff98322337951c56398e79d51815acbf955`
- `Linux 5.7`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.