How to fix CVE-2025-67186?

Within 24 hours: Identify and inventory all A950Rg devices in your environment and isolate them from untrusted networks if possible; establish monitoring for exploit attempts. Within 7 days: Contact the vendor for patch availability and escalated timeline; implement network segmentation to limit device exposure; deploy WAF rules to block known exploit patterns if applicable. Within 30 days: Apply firmware patches immediately upon vendor release; conduct forensic review of device logs for signs of compromise; implement additional network access controls and threat detection signatures.

Is A950rg Firmware affected by CVE-2025-67186?

A critical buffer overflow vulnerability (CVE-2025-67186) affects A950Rg devices running firmware up to version 4.1.2cu.5204_b20210112, with a CVSS score of 9.8 and active public exploits available.

CVE-2025-67186

CRITICAL

2026-02-03 [email protected]

9.8

CVSS 3.1

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

PoC Detected

Feb 10, 2026 - 14:17 vuln.today

Public exploit code

CVE Published

Feb 03, 2026 - 18:16 nvd

CRITICAL 9.8

Description

TOTOLINK A950RG V4.1.2cu.5204_B20210112 contains a buffer overflow vulnerability in the setUrlFilterRules interface of /lib/cste_modules/firewall.so. The vulnerability occurs because the `url` parameter is not properly validated for length, allowing remote attackers to trigger a buffer overflow, potentially leading to arbitrary code execution or denial of service.

Analysis

TOTOLINK A950RG router firmware has a buffer overflow in setUrlFilterRules that allows remote attackers to execute code through the router's management interface.

Technical Context

TOTOLINK A950RG V4.1.2cu.5204_B20210112 has a CWE-120 buffer overflow in the setUrlFilterRules function of /cgi-bin/cstecgi.cgi, triggered by oversized URL filter rule parameters.

Affected Products

['TOTOLINK A950RG V4.1.2cu.5204_B20210112']

Remediation

Update firmware. Restrict management interface access. Consider replacing end-of-life routers.

Priority Score

Low Medium High Critical

KEV: 0

EPSS: +0.8

CVSS: +49

POC: +20

CVE-2025-67186 vulnerability details – vuln.today

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CVE-2025-67186

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CVE-2025-67186

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Lifecycle Timeline

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Description

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