# Buffer Overflow Found in lwIP SMTP Client

Published: 2026-10-06 · Severity: routine · Sectors: energy, infrastructure
Canonical: https://vorant.io/reports/d52d0f14-54d3-57c7-b8e7-06ec9818aec8/buffer-overflow-found-in-lwip-smtp-client

> A buffer overflow in Savannah lwIP SMTP client 2.2.1 could crash devices or enable remote code execution; no active exploitation reported.

CISA published an ICS advisory for a buffer overflow vulnerability in the Savannah lwIP SMTP client version 2.2.1, a lightweight TCP/IP stack commonly embedded in resource-constrained devices used across critical infrastructure sectors including Energy and Water/Wastewater Systems. The vendor is headquartered in Sweden and the software is deployed worldwide.

Successful exploitation could crash the affected device or, under a buffer overflow condition, potentially allow remote code execution. The vulnerability was reported directly to Savannah by researcher xchglabs and publicly disclosed only after a fix was released, indicating coordinated disclosure rather than active exploitation in the wild.

CISA recommends standard ICS defense-in-depth practices: minimizing network exposure of control system devices, ensuring they are not internet-accessible, isolating control system networks behind firewalls separate from business networks, and using secure remote access methods such as updated VPNs when remote access is required. Organizations using lwIP in embedded or ICS products should identify affected deployments and apply vendor patches once available.

## Mentioned in this report

- Vulnerabilities: CVE-2026-15340

1 more detection for this report is in the app: the rules that match its indicators, every rule converted to Splunk SPL and Elastic, Microsoft Defender XDR KQL wherever Defender records the activity, and the YARA and Suricata. A new account gets three days of them free.

Source reporting: https://www.cisa.gov/news-events/ics-advisories/icsa-26-279-02

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