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CISA advisoryVulnerabilitiesPublished September 22, 2026

lwIP TCP/IP Stack MQTT Client Application

View CSAF Summary Successful exploitation of this vulnerability could allow an attacker to gain full code execution on the device. The following versions of lwIP TCP/IP Stack MQTT Client Application are affected: MQTT Client Application >=2.0.1|<=2.2.1 (CVE-2026-87121) CVSS Vendor Equipment Vulnerabilities v3 9.8 lwIP lwIP TCP/IP Stack MQTT Client Application Out-of-bounds Write Background Critical Infrastructure Sectors: Chemical, Communications, Critical Manufacturing, Energy, Financial Services, Healthcare and Public Health, Transportation Systems, Water and Wastewater Systems Countries/Areas Deployed: Worldwide Company Headquarters Location: Sweden Vulnerabilities Expand All + CVE-2026-87121 The affected product is vulnerable to an out-of-bounds write, which may allow an attacker to gain full code execution on the device. View CVE Details Affected Products lwIP TCP/IP Stack MQTT Client Application Vendor: lwIP Product Version: lwIP MQTT Client Application: >=2.0.1|<=2.2.1 Product Status: known_affected Remediations Mitigation Users of lwIP are encouraged to update their version of lwIP using the repository found at https://savannah.nongnu.org/projects/lwip. The commit identifi…

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Tags
CISA, healthcare
Related exam domains
CISSP 8: Software Development Security; CISM 2: Information Security Risk Management
Source record id
/node/25521
First seen by InfoSec Signals
9/23/2026

Exam domain labels come from a keyword heuristic and are study hints, not an official mapping. The summary is the publisher's own text, shortened; the linked record is authoritative.