CVE-2026-7218: Totolink N300RT Buffer Overflow Exploited Remotely
The National Vulnerability Database reports a critical buffer overflow, CVE-2026-7218, in Totolink N300RT firmware version 3.4.0-B20250430. This vulnerability resides within the is_cmd_string_valid function in the /boafrm/formWsc component of the libapmib.so library. Attackers can trigger this flaw by manipulating the localPin argument.
This is not a theoretical vulnerability. The National Vulnerability Database confirms that a remote exploit for CVE-2026-7218 is publicly available. With a CVSS score of 7.2 (HIGH), this vulnerability allows authenticated remote attackers to achieve high impact on confidentiality, integrity, and availability. The prerequisite of high privileges (PR:H) indicates an attacker would likely need to bypass initial authentication, but the remote vector (AV:N) makes it dangerous.
Defenders need to understand the attacker’s calculus here. While PR:H might seem like a barrier, the public exploit availability means sophisticated attackers will chain this with other initial access methods. Once inside, this buffer overflow offers a reliable path to deeper system compromise. Organizations running these specific Totolink devices are at severe risk.
What This Means For You
- If your organization uses Totolink N300RT routers, specifically firmware version 3.4.0-B20250430, identify these devices immediately. Given the public exploit and high CVSS score, these are prime targets for remote compromise. Isolate them from critical networks and apply any vendor patches as soon as they become available. If no patch exists, consider immediate replacement or removal from service.
Related ATT&CK Techniques
🛡️ Detection Rules
5 rules · 6 SIEM formats5 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
Web Application Exploitation Attempt — CVE-2026-7218
title: Web Application Exploitation Attempt — CVE-2026-7218
id: scw-2026-04-28-1
status: experimental
level: high
description: |
Detects common exploitation patterns targeting web applications. Review CVE-2026-7218 advisories for specific indicators.
author: SCW Feed Engine (auto-generated)
date: 2026-04-28
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-7218/
tags:
- attack.initial_access
- attack.t1190
logsource:
category: webserver
detection:
selection:
cs-uri-query|contains:
- '..'
- 'SELECT'
- 'UNION'
- '<script'
- 'cmd='
- '/etc/passwd'
condition: selection
falsepositives:
- Legitimate activity from CVE-2026-7218
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-7218 | Buffer Overflow | Totolink N300RT version 3.4.0-B20250430 |
| CVE-2026-7218 | Buffer Overflow | Vulnerable function: is_cmd_string_valid in /boafrm/formWsc (libapmib.so) |
| CVE-2026-7218 | Buffer Overflow | Vulnerable argument: localPin |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | April 28, 2026 at 06:16 UTC |
This content was AI-rewritten and enriched by Shimi's Cyber World based on the original source. All intellectual property rights remain with the original author.
Believe this infringes your rights? Submit a takedown request.
Related coverage
CVE-2026-7223: BigSweetPotatoStudio HyperChat SSRF Vulnerability
CVE-2026-7223 — A vulnerability was identified in BigSweetPotatoStudio HyperChat up to 2.0.0-alpha.63. Affected by this issue is the function fetch of the file packages/core/src/http/aiProxyMiddleware.mts of...
TencentCloudBase CloudBase-MCP SSRF Vulnerability (CVE-2026-7221)
CVE-2026-7221 — A vulnerability was found in TencentCloudBase CloudBase-MCP up to 2.17.0. Affected is the function openUrl of the file mcp/src/interactive-server.ts of the component open-url...
CVE-2026-7220: FastlyMCP Command Injection Exposes Infrastructure
CVE-2026-7220 — A vulnerability has been found in jackwrichards FastlyMCP up to 6f3d0b0e654fc51076badc7fa16c03c461f95620. This impacts an unknown function of the file fastly-mcp.mjs of the component...