What is the CVSS score of CVE-2026-26731?

CVE-2026-26731 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Is there a public PoC exploit available for CVE-2026-26731?

Yes, a public proof-of-concept exploit is available for CVE-2026-26731. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-26731?

Within 24 hours: Identify and inventory all TOTOLINK A3002RU V2.1.1-B20211108.1455 devices in the network and isolate affected units from critical systems. Within 7 days: Implement network segmentation to restrict router management access, disable remote administration features if enabled, and deploy WAF rules to block malicious formDnsv6 requests. Within 30 days: Replace affected routers with patched or alternative vendor models, or prepare emergency patching procedures once vendor patches become available.

A3002ru Firmware CVE-2026-26731

HIGH

Out-of-bounds Write (CWE-787)

2026-02-17 cve@mitre.org

Buffer Overflow Memory Corruption A3002ru Firmware TOTOLINK

8.8

CVSS 3.1 · NVD

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Authenticate to router management interface
Exploit

Send malicious formDnsv6 request with oversized routernamer parameter
Execution

Trigger stack buffer overflow in formDnsv6 function
Impact

Execute arbitrary code with router privileges

Vulnerability Assessment

Weakness	CWE CWE-787 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V15 - Secure Coding and Architecture Bounds checking, write limits MITRE ATT&CK 2 techniques across 2 tactics: Execution, Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Exploitation Conditions	TOTOLINK A3002RU V2.1.1-B20211108.1455 with formDnsv6 function accessible. Requires valid authentication credentials to router management interface (PR:L). Affected firmware version must be unpatched.
Impact	CVSS 8.8 (HIGH). Attack vector: Network. Complexity: Low. Privileges required: Low. User interaction: None. Public exploit/POC available.
Exploit ScenarioDerived	An attacker could exploit this vulnerability to compromise the affected system.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

No patch listed yet 0.1% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

Remote code execution in TOTOLIK A3002RU V2.1.1 firmware results from a stack-based buffer overflow in the DNS configuration function that can be exploited by authenticated network users. Public exploit code exists for this vulnerability, and attackers with valid credentials can achieve full system compromise including code execution and data manipulation. No patch is currently available.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 21:55 CVSS 8.8

TOTOLINK A3002RU V2.1.1-B20211108.1455 was discovered to contain a stack-based buffer overflow via the routernamer`parameter in the formDnsv6 function. [CVSS 8.8 HIGH]

RemediationAI

Monitor vendor advisories for a patch. Enable ASLR, DEP/NX, and stack canaries where possible. Restrict network access to the affected service where possible.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Classified as CWE-787 (Out-of-bounds Write). Affects the formDnsv6 component of A3002Ru Firmware. TOTOLINK A3002RU V2.1.1-B20211108.1455 was discovered to contain a stack-based buffer overflow via the routernamer`parameter in the formDnsv6 function.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 8.8 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

PoC Detected

Mar 16, 2026 - 16:16 vuln.today

Public exploit code

CVE Published

Feb 17, 2026 - 19:21 nvd

HIGH 8.8

DescriptionNVD

TOTOLINK A3002RU V2.1.1-B20211108.1455 was discovered to contain a stack-based buffer overflow via the routernamer`parameter in the formDnsv6 function.

Executive ViewAI

Why It Matters

A high-severity buffer overflow vulnerability (CVE-2026-26731) affecting TOTOLIK A3002RU routers allows remote attackers to execute arbitrary code with a CVSS score of 8.8. Organizations using this router model are at immediate risk of unauthorized access and network compromise, with active exploit code publicly available. No vendor patch currently exists, requiring immediate mitigation measures to prevent potential breach.

Business Impact: High

Compensating Controls

Implement network access controls to restrict administrative access to the router; disable or restrict access to the formDnsv6 function if possible through firmware configuration; deploy Web Application Firewall (WAF) rules to filter malicious routernamer parameter inputs; implement network segmentation to isolate routers from critical assets; monitor for suspicious DNS configuration changes and unauthorized administrative access attempts; consider replacing vulnerable routers with alternative vendors pending patch availability.

Threat Intelligence Overview

EPSS Score

0.1%

Top 67% exploitable

Exploit

POC

Public exploit code exists

Data Quality

5 sources

Confidence: Medium

NVD

CVE.org

EPSS

GitHub

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC Yes

EPSS 0.1%

Patch available No

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

Poc

System Exposure· derived

Open

Automatable· derived

Human Impact

High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +44

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Buffer Overflow HIGH

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Memory Corruption HIGH

Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.