CVE-2026-112062: lwIP through 2.2.1 Stack Out-of-Bounds Write via mDNS Search Response Handler
lwIP through 2.2.1 contains a stack out-of-bounds write vulnerability in mdnshandleresponse that allows adjacent attackers to corrupt stack memory by sending mDNS responses with invalid domain names. Attackers on the local link can send multicast PTR answers with oversized RDLENGTH or SRV answers with RDLENGTH below 6 during a service search, overflowing a 256-byte stack buffer and crashing the device.
Affected Software
Event History
Frequently Asked Questions
Who can exploit this issue?
An attacker must be on the same local network link as the affected device. No privileges or user interaction are required.
When is an affected device vulnerable to malicious responses?
The vulnerable handler is reached during an mDNS service search. The attacker can send multicast PTR answers with an oversized RDLENGTH or SRV answers whose RDLENGTH is less than 6.
What is the expected impact of a successful attempt?
Malformed responses can write beyond a 256-byte stack buffer and corrupt adjacent stack memory. The described outcome is a device crash; the provided data does not establish code execution.