---
id: "CVE-2026-43835"
kind: "vulnerability"
aliases: ["CVE-2026-43835"]
title: "Firmware upgrade accepts forged images, letting an authenticated user persist on device"
severity: "high"
cvss: 8.6
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "ADAM-3600 EdgeLink", "fixed": ["2.8.5.0"], "affected": "< 2.8.5.0", "ecosystem": "vendor"}]
ecosystems: []
tags: ["adam-3600", "advantech", "edgelink", "firmware", "ics", "infrastructure", "network-appliance", "rtu"]
not_affected_if: ["firmware-2.8.5.0-or-later", "no-authenticated-access", "unauthenticated-only-access"]
published_at: "2026-10-20T08:16:44+00:00"
first_seen_at: "2026-10-23T21:57:20+00:00"
updated_at: "2026-10-24T00:17:20+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43835", "first_seen_at": "2026-10-23T21:57:20+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-24T00:17:20+00:00"}]
---

# Firmware upgrade accepts forged images, letting an authenticated user persist on device

Advantech ADAM-3600 EdgeLink RTU firmware before 2.8.5.0 does not properly verify firmware upgrade files. An authenticated admin-level user can upload a forged image and persistently take over the device. Part of a batch of 30 fixes released together.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:ADAM-3600 EdgeLink affected < 2.8.5.0 fixed 2.8.5.0

## How to check

Open the ADAM-3600 web UI or EdgeLink system info and read the firmware version. Anything below 2.8.5.0 is affected. Also check whether the web or management interface is reachable from untrusted networks.

## Fix

Upgrade ADAM-3600 EdgeLink firmware to 2.8.5.0 or later (download from the Advantech ADAM-3600 firmware support page). Until then, restrict network access to the device, use strong unique admin credentials, and only install firmware obtained directly from Advantech.

## Timeline

- 2026-10-23T21:57:20+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-43835
- 2026-10-24T00:17:20+00:00 analyst — Advantech ADAM-3600 EdgeLink, advisory ACIRT-261001 (PDF item 7, NN-2025-0126), one of 30 CVEs (43829-43858) fixed in v2.8.5.0; CWE-345. Vendor fix is asymmetric digital signature verification of firmware. No exploitation or PoC reported (CISA SSVC exploitation none). Found by Nozomi Networks. Did not search social: ICS device, no CVE-specific conversation expected. Fixed-version page for 2.8.5.0 download not read; 2.8.5.1 is mentioned in the PDF for a different CVE.

## Documents

- [advisory] Advantech: Vulnerabilities Identified in ADAM-3600 (ACIRT-261001) https://advcloudfiles.advantech.com/cms/de8e2d94-10ab-470e-ac6f-d2e5434f4ec4/Security%20Advisory%20PDF%20File/SECURITY-ADVISORY----ADAM-3600.pdf
- [describes] CSA Singapore AL-2026-149: Advantech ADAM-3600 EdgeLink multiple vulnerabilities https://www.csa.gov.sg/alerts-and-advisories/alerts/al-2026-149
- [mentions] Canadian Cyber Centre AV26-1065: Advantech ADAM-3600 prior to v2.8.5.0 https://www.cyber.gc.ca/en/alerts-advisories/control-systems-advantech-security-advisory-av26-1065

## From the sources

A vulnerability in the firmware upgrade functionality could allow an authenticated attacker to upload a forged firmware upgrade file, potentially compromising the device permanently.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_