Vulnerability · Published Oct 18, 2026 · Assigned by VulnCheck

CVE-2026-112062lwIP through 2.2.1 Stack Out-of-Bounds Write via mDNS Search Response Handler

Medium 5.9

In plain English

A medium-severity stack buffer overflow in lwIP from lwIP. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities).

Severity (CVSS 3.1)5.9Medium

Exploit odds (30 days)0.4%top 70.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	lwip	no fix listed	DEBIAN-CVE-2026-112062
Debian:13	lwip	no fix listed	DEBIAN-CVE-2026-112062
Debian:14	lwip	no fix listed	DEBIAN-CVE-2026-112062
Ubuntu:26.10	lwip	no fix listed	UBUNTU-CVE-2026-112062

Affected products (as reported)

Vendor	Product	Versions
lwIP	lwIP	0 – through 2.2.1

Weakness: CWE-121 · Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H

References

https://hackmd.io/@haindpwn/lwip-mdns-search-result-domain-oob-write third-party-advisory
https://github.com/lwip-tcpip/lwip/commit/ab2f69c7d8980c01cdd67ed4b23ac61118ed0205 patch
https://github.com/lwip-tcpip/lwip/blob/STABLE-2_2_1_RELEASE/src/apps/mdns/mdns.c technical-description
VulnCheck Advisory: lwIP through 2.2.1 Stack Out-of-Bounds Write via mDNS Search Response Handler third-party-advisory
https://hackmd.io/@haindpwn/cve-2026-112062-lwip-mdns-search-result-domain-oob-write exploit