---
id: "CVE-2026-40615"
kind: "vulnerability"
aliases: ["CVE-2026-40615"]
title: "TOTOLINK X2000R router: crafted request overflows stack and runs code"
severity: "critical"
cvss: 9.1
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "X2000R", "fixed": [], "affected": "TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327", "ecosystem": "vendor"}]
ecosystems: []
tags: ["authenticated", "embedded-firmware", "infrastructure", "router", "totolink", "x2000r"]
not_affected_if: ["auth-required", "other-firmware-version", "parent-control-unused", "wan-admin-disabled"]
published_at: "2026-10-20T21:17:18+00:00"
first_seen_at: "2026-10-23T21:57:21+00:00"
updated_at: "2026-10-23T23:15:46+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40615", "first_seen_at": "2026-10-23T21:57:21+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-23T23:15:46+00:00"}]
---

# TOTOLINK X2000R router: crafted request overflows stack and runs code

Stack buffer overflow in the TOTOLINK X2000R web admin (boa). A logged-in user can POST an oversized deviceName to /boafrm/formParentControl (with modPCRule or addPCUrl set) and run code on the router. Found by Cisco Talos. Admin login is required (CVSS PR:H), but the flaw can be reached over the network. No vendor fix has been published.

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

## Affected

- vendor:X2000R affected TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327 fixed ?

## How to check

Open the router admin page, go to system status and read the firmware version. Firmware TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327 is confirmed vulnerable. Other builds are untested. Also check whether the admin interface is reachable from WAN, for example by testing the router's public IP on its web admin port from outside your network.

## Fix

No fixed firmware as of 2026-10-20. Check the TOTOLINK X2000R download page for a build newer than B20250421.1327. Until one exists: turn off remote/WAN administration, restrict admin access to a trusted LAN, change the default admin password, and replace the router if it cannot be isolated.

## Timeline

- 2026-10-23T21:57:21+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-40615
- 2026-10-23T23:15:46+00:00 analyst — Read Talos TALOS-2026-2393 (primary): authenticated strcpy of deviceName in formParentControl, /bin/boa, MIPS. No vendor fix: Talos timeline shows vendor acknowledged 2026-06-25 but no patch by 2026-10-20. No exploitation or public PoC found; X not checked. Sibling X2000R CVEs from same Talos batch.

## Documents

- [advisory] TALOS-2026-2393: Totolink X2000R formParentControl deviceName stack overflow https://talosintelligence.com/vulnerability_reports/TALOS-2026-2393

## From the sources

A stack-based buffer overflow vulnerability exists in the boa formParentControl deviceName functionality of X2000R (version(s): TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327). A specially crafted HTTP request can lead to arbitrary code execution. An attacker can make an authenticated HTTP request to trigger this vulnerability.

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