Cyber Posture

CVE-2026-4008

HighPublic PoC

Published: 12 March 2026

Published
12 March 2026
Modified
02 April 2026
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0011 29.2th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-4008 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Tenda W3 Firmware. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 29.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Requires validation of POST parameters such as 'index' and 'GO' to prevent stack-based buffer overflows from malformed or oversized inputs in the /goform/wifiSSIDset handler.

prevent

Implements memory protections like stack canaries, ASLR, and DEP to mitigate exploitation of stack-based buffer overflows even if input validation fails.

prevent

Mandates timely identification, reporting, and correction of the specific buffer overflow flaw in Tenda W3 firmware version 1.0.0.3(2204) via patching or upgrades.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
Why these techniques?

Stack-based buffer overflow in router web form handler (/goform/wifiSSIDset) enables authenticated remote code execution on a network-accessible device, directly facilitating T1190 (Exploit Public-Facing Application) for initial access and T1068 (Exploitation for Privilege Escalation) to achieve full device compromise from low-privilege web credentials.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

A flaw has been found in Tenda W3 1.0.0.3(2204). This issue affects some unknown processing of the file /goform/wifiSSIDset of the component POST Parameter Handler. Executing a manipulation of the argument index/GO can lead to stack-based buffer overflow. It is…

more

possible to launch the attack remotely. The exploit has been published and may be used.

Deeper analysisAI

CVE-2026-4008 is a stack-based buffer overflow vulnerability affecting the Tenda W3 router on firmware version 1.0.0.3(2204). The flaw occurs in an unknown processing function of the POST Parameter Handler component when handling the /goform/wifiSSIDset file, where manipulation of the "index" or "GO" arguments triggers the overflow. It is associated with CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), CWE-121 (Stack-based Buffer Overflow), and CWE-787 (Out-of-bounds Write).

The vulnerability carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating it is exploitable over the network with low attack complexity and requires only low privileges, such as those of an authenticated user, with no user interaction needed. Successful exploitation can result in high impacts to confidentiality, integrity, and availability, potentially allowing remote code execution and full device compromise.

Proof-of-concept exploits have been publicly released on GitHub, including repositories at https://github.com/Svigo-o/Tenda_vul/tree/main/tenda-w3-formwrlSSIDset-go-buffer-overflow and https://github.com/Svigo-o/Tenda_vul/tree/main/tenda-w3-formwrlSSIDset-index-buffer-overflow, demonstrating the buffer overflows. Further details are available via VulDB at https://vuldb.com/?ctiid.350531, https://vuldb.com/?id.350531, and https://vuldb.com/?submit.769182, though no specific patch or mitigation guidance is outlined in the referenced materials.

Details

CWE(s)

Affected Products

tenda
w3 firmware
1.0.0.3\(2204\)

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CVE-2026-4042Same vendor: Tenda
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CVE-2026-4902Same vendor: Tenda

References