What is the CVSS score of CVE-2026-3809?

CVE-2026-3809 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-2026-3809?

Yes, a public proof-of-concept exploit is available for CVE-2026-3809. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-3809?

Within 24 hours: Inventory all Tenda FH1202 devices running firmware 1.2.0.14(408) and isolate affected units from production networks if possible. Within 7 days: Implement network segmentation to restrict access to the vulnerable /goform/NatStaticSetting endpoint and apply WAF rules to block exploitation attempts. Within 30 days: Monitor Tenda's security advisories for patch availability; prepare and test firmware updates immediately upon release.

Fh1202 Firmware CVE-2026-3809

HIGH

Buffer Overflow (CWE-119)

2026-03-09 cna@vuldb.com

Buffer Overflow Stack Overflow Tenda Fh1202 Firmware

8.8

CVSS 3.1 · NVD

View

Attack ChainAIDerived

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

Access

Authenticate to Tenda FH1202 web interface
Delivery

Send crafted POST to /goform/NatSaticSetting
Exploit

Inject oversized page parameter
Execution

Overflow stack buffer in fromNatStaticSetting
Impact

Execute arbitrary code with device privileges

Vulnerability Assessment

Weakness	CWE CWE-119 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V15 - Secure Coding and Architecture Bounds checking, buffer size validation MITRE ATT&CK 2 techniques across 2 tactics: Execution,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	Tenda FH1202 firmware version 1.2.0.14(408) with web management interface enabled; valid login credentials required; /goform/NatSaticSetting endpoint must be accessible; stack-based buffer overflow triggered via page parameter in POST request to vulnerable function.
Impact	CVSS 8.8 (HIGH). Attack vector: Network. Complexity: Low. Privileges required: Low. User interaction: None. Exploitable via remote/network. Public exploit/POC available.
Exploit ScenarioDerived	A remote attacker could exploit this vulnerability to stack-based buffer overflow.

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

Stack-based buffer overflow in Tenda FH1202 firmware version 1.2.0.14(408) allows remote authenticated attackers to achieve complete system compromise through manipulation of the page parameter in the /goform/NatStaticSetting function. Public exploit code exists for this vulnerability and no patch is currently available. The flaw requires valid credentials but can be exploited over the network with no user interaction.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 21:56 CVSS 8.8

A flaw has been found in Tenda FH1202 1.2.0.14(408). The impacted element is the function fromNatStaticSetting of the file /goform/NatSaticSetting. [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-119 (Buffer Overflow). Affects Fh1202 Firmware. A flaw has been found in Tenda FH1202 1.2.0.14(408). The impacted element is the function fromNatStaticSetting of the file /goform/NatSaticSetting. Executing a manipulation of the argument page can lead to stack-based buffer overflow. The attack may be launched remotely. The exploit has been published and may be used.

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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 09, 2026 - 15:30 vuln.today

Public exploit code

CVE Published

Mar 09, 2026 - 08:16 nvd

HIGH 8.8

DescriptionCVE.org

A flaw has been found in Tenda FH1202 1.2.0.14(408). The impacted element is the function fromNatStaticSetting of the file /goform/NatSaticSetting. Executing a manipulation of the argument page can lead to stack-based buffer overflow. The attack may be launched remotely. The exploit has been published and may be used.

Executive ViewAI

Why It Matters

A HIGH severity vulnerability (CVE-2026-3809, CVSS 8.8) affects Tenda FH1202 network devices, allowing potential remote exploitation through a NAT configuration function. Organizations using this device model are at significant risk of unauthorized access and network compromise, despite the current low real-world exploitation rate (EPSS 0.1%).

Business Impact: High

Compensating Controls

Implement network segmentation to restrict administrative access to affected devices; deploy WAF/IDS rules to monitor and block requests to /goform/NatStaticSetting endpoint; disable NAT Static Setting functionality if operationally feasible; restrict management interface access via firewall rules to authorized IP ranges only; enable detailed logging and monitoring for suspicious configuration changes.

Threat Intelligence Overview

EPSS Score

0.1%

Top 77% 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.

Stack-based Buffer Overflow HIGH

A stack-based buffer overflow occurs when a program writes more data to a buffer located on the stack than it was allocated to hold.