---
id: CVE-2026-30872
title: OpenWrt Project is a Linux operating system targeting embedded devices
summary: >-
  OpenWrt Project is a Linux operating system targeting embedded devices. In
  versions prior to 24.10.6 and 25.12.1, the mdns daemon has a Stack-based
  Buffer Overflow vulnerability in the match_ipv6_addresses function, triggered
  when proces…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-121
vendor: openwrt
product: openwrt
affected:
  - openwrt < 24.10.6
  - 'openwrt >= 25.12.0, < 25.12.1'
patched:
  - openwrt 25.12.1
published: '2026-03-19'
updated: '2026-11-03'
sourceUpdated: '2026-11-03T23:17:42.170'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-30872'
references:
  - url: 'https://github.com/openwrt/openwrt/releases/tag/v24.10.6'
    label: security-advisories@github.com
  - url: 'https://github.com/openwrt/openwrt/releases/tag/v25.12.1'
    label: security-advisories@github.com
  - url: 'https://github.com/openwrt/openwrt/security/advisories/GHSA-mpgh-v658-jqv5'
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-03-25T03:56:14.448125Z'
scores:
  nvd: 9.8
  cna: 9.5
epss: 0.02359
epssPercentile: 0.83834
ingestedAt: '2026-11-05T06:38:03.609Z'
---

## Overview

OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to 24.10.6 and 25.12.1, the mdns daemon has a Stack-based Buffer Overflow vulnerability in the match_ipv6_addresses function, triggered when processing PTR queries for IPv6 reverse DNS domains (.ip6.arpa) received via multicast DNS on UDP port 5353. During processing, the domain name from name_buffer is copied via strcpy into a fixed 256-byte stack buffer, and then the reverse IPv6 request is extracted into a buffer of only 46 bytes (INET6_ADDRSTRLEN). Because the length of the data is never validated before this extraction, an attacker can supply input larger than 46 bytes, causing an out-of-bounds write. This allows a specially crafted DNS query to overflow the stack buffer in match_ipv6_addresses, potentially enabling remote code execution. This issue has been fixed in versions 24.10.6 and 25.12.1.

## Affected

- `openwrt < 24.10.6`
- `openwrt >= 25.12.0, < 25.12.1`

## Remediation

Upgrade past the affected range:

- `openwrt 25.12.1`