Description
lwIP through 2.2.1 contains a stack out-of-bounds write vulnerability in mdns_handle_response 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.
References5
- github.com/lwip-tcpip/lwip/blob/STABLE-2_2_1_RELEASE/src/apps/m…
- github.com/lwip-tcpip/lwip/commit/ab2f69c7d8980c01cdd67ed4b23ac…
- hackmd.io/@haindpwn/lwip-mdns-search-result-domain-oob-write
- www.vulncheck.com/advisories/lwip-through-2.2.1-stack-out-of-bo…
- hackmd.io/@haindpwn/cve-2026-112062-lwip-mdns-search-result-dom…
Metrics
- CVSS 3.1
-
5.9
MEDIUM
Score source: CNA
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H - CVSS 4.0
-
6.0
MEDIUM
Score source: CNA
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 30 · as of 10 November 2026
- CWE
- CWE-121
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.