What is the CVSS score of CVE-2026-24111?

CVE-2026-24111 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Is there a public PoC exploit available for CVE-2026-24111?

Yes, a public proof-of-concept exploit is available for CVE-2026-24111. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-24111?

Within 24 hours: Identify all Tenda W20E V4.0br devices in your network inventory and isolate affected units from production traffic if business-critical. Within 7 days: Contact Tenda for patch status and timelines; implement network segmentation to restrict router management access to trusted administrative networks only. Within 30 days: Deploy replacement hardware from an alternative vendor or apply any available firmware update from Tenda once released; conduct network forensics on affected devices for signs of compromise.

W20e Firmware CVE-2026-24111

CRITICAL

Classic Buffer Overflow (CWE-120)

2026-03-02 cve@mitre.org

Buffer Overflow Tenda W20e Firmware

9.8

CVSS 3.1 · NVD

View

Attack ChainAIDerived

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

Access

Send HTTP request with oversized userInfo parameter
Exploit

Trigger sscanf buffer overflow in addAuthUser function
Impact

Execute arbitrary code on router

Vulnerability Assessment

Weakness	CWE CWE-120 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V15 - Secure Coding and Architecture Buffer copy size validation MITRE ATT&CK 1 technique across 1 tactic: Execution The technique list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	Tenda W20E firmware version V4.0br_V15.11.0.6 with addAuthUser function accessible via network without authentication. No special conditions — remote unauthenticated exploitation against default W20E configurations.
Impact	CVSS 9.8 with PoC.
Exploit ScenarioDerived	Overflow via crafted input.

Act Now Prioritize within 24-48h. Why: CRITICAL severity + public POC available.

No patch listed yet 0.1% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

Tenda W20E has a fourth buffer overflow vulnerability.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 21:55 CVSS 9.8

Fourth Tenda W20E overflow.

RemediationAI

Update firmware.

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

CWE-120.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 9.8 CRITICAL

AV:N/AC:L/PR:N/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

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

PoC Detected

Mar 05, 2026 - 16:16 vuln.today

Public exploit code

CVE Published

Mar 02, 2026 - 15:16 nvd

CRITICAL 9.8

DescriptionCVE.org

An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may exploit the vulnerability by specifying the value of userInfo. When userInfo is passed into the addAuthUser function and processed by sscanf without size validation, it could lead to buffer overflow.

Executive ViewAI

Why It Matters

A critical vulnerability (CVSS 9.8) affecting Tenda W20E routers allows unauthenticated remote code execution through the userInfo parameter. Organizations using this device model are at immediate risk of complete system compromise, data theft, and network infiltration, with active public exploits already available.

Business Impact: Severe

Compensating Controls

Disable remote management access to the router's web interface; restrict router administrative access to a dedicated secure network segment with strict firewall rules; implement network segmentation to limit lateral movement from compromised router; monitor for suspicious userInfo parameter patterns in router logs; consider deploying WAF rules to block malformed userInfo requests if router sits behind a proxy; evaluate immediate hardware replacement as the most reliable mitigation given exploit availability and lack of patch.

Threat Intelligence Overview

EPSS Score

0.1%

Top 84% exploitable

Exploit

POC

Public exploit code exists

Data Quality

4 sources

Confidence: Medium

NVD

CVE.org

EPSS

GitHub

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 CRITICAL

CISA KEV No

Public POC Yes

EPSS 0.1%

Patch available No

Active threat No

Deciding rule

CRITICAL severity + public POC available

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

Out-of-Cycle

Exploitation· derived

Poc

System Exposure· derived

Open

Automatable· derived

Yes

Human Impact

Very High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +49

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.