---
id: CVE-2026-115863
title: >-
  ConnMan through 2.0 has a stack-based buffer overflow via a DHCPv6 Reply
  message
summary: >-
  ConnMan through 2.0 has a stack-based buffer overflow via a DHCPv6 Reply
  message. This occurs in get_domains in gdhcp/client.c. It copies a fixed
  NS_MAXDNAME (1025) bytes from a DHCPv6 DOMAIN_LIST (option 24) value into a
  1026-byte stack…
severity: high
cvss: 7.6
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H'
cvssSource: cna
cwe:
  - CWE-121
vendor: ConnMan
product: ConnMan
affected:
  - ConnMan <= 2.0
published: '2026-10-23'
updated: '2026-10-23'
sourceUpdated: '2026-10-23T17:35:18.517Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-115863'
references:
  - url: >-
      https://lore.kernel.org/connman/179274561161.81299.4579745057858200074@pm.me/
  - url: >-
      https://git.kernel.org/pub/scm/network/connman/connman.git/tree/gdhcp/client.c
  - url: >-
      https://git.kernel.org/pub/scm/network/connman/connman.git/commit/?id=bb06c47101ca243fa5c04fb4b03fe2a12420d280
tags:
  - cve.org
ingestedAt: '2026-10-23T18:33:41.110Z'
---

## Overview

ConnMan through 2.0 has a stack-based buffer overflow via a DHCPv6 Reply message. This occurs in get_domains in gdhcp/client.c. It copies a fixed NS_MAXDNAME (1025) bytes from a DHCPv6 DOMAIN_LIST (option 24) value into a 1026-byte stack buffer dns_name regardless of the actual option length, then walks DNS labels with an unbounded "c += jump + 1" loop. A crafted DHCPv6 REPLY with a DOMAIN_LIST option of >= 1025 non-zero bytes makes the label walk leave the buffer and read/write '.' past its end in attacker-chosen strides. An on-link attacker can trigger this without authentication via a forged Router Advertisement (O=1) and a forged DHCPv6 REPLY matching xid/CLIENTID with a long DOMAIN_LIST. The impact is unauthenticated on-link crash of connmand (runs as root). This was introduced in bb06c47.

## Affected

- `ConnMan <= 2.0`

## Remediation

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