CVE-2026-30872
Stack-Based Buffer Overflow in OpenWrt mdns Enables RCE
Publication date: 2026-03-19
Last updated on: 2026-03-24
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| openwrt | openwrt | to 24.10.6 (exc) |
| openwrt | openwrt | From 25.12.0 (inc) to 25.12.1 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-121 | A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the mdns daemon of the OpenWrt Project's Linux operating system for embedded devices. Specifically, in versions before 24.10.6 and 25.12.1, there is a stack-based buffer overflow in the match_ipv6_addresses function. The issue occurs when processing PTR queries for IPv6 reverse DNS domains (.ip6.arpa) received via multicast DNS on UDP port 5353.
The vulnerability arises because the domain name from name_buffer is copied using strcpy into a fixed 256-byte stack buffer without validating the length. Then, the reverse IPv6 request is extracted into a smaller buffer of only 46 bytes. Since the length of the data is never checked before this extraction, an attacker can supply input larger than 46 bytes, causing an out-of-bounds write and overflowing the stack buffer.
This overflow can potentially allow remote code execution by an attacker sending a specially crafted DNS query.
How can this vulnerability impact me? :
This vulnerability can have severe impacts as it allows an attacker to perform a stack-based buffer overflow remotely via specially crafted multicast DNS queries. The overflow can lead to remote code execution on the affected device.
Remote code execution means an attacker could potentially take control of the device, execute arbitrary code, disrupt services, or use the device as a foothold to attack other systems within the network.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade your OpenWrt system to version 24.10.6 or later, or 25.12.1 or later, where the issue has been fixed.