Cyber Posture

CVE-2026-5609

HighPublic PoC

Published: 06 April 2026

Published
06 April 2026
Modified
30 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 0.0009 25.6th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-5609 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Tenda I12 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 25.6th 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). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly validates the index/wl_radio parameter input to prevent stack-based buffer overflow exploitation in the formwrlSSIDset function.

prevent

Requires identification, reporting, and correction of the specific buffer overflow flaw in the Tenda i12 firmware via patching or updates.

prevent

Implements runtime memory protections like stack canaries or guard pages to mitigate stack buffer overflow attempts leading to arbitrary code execution.

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.
Why these techniques?

The CVE describes a remotely exploitable stack-based buffer overflow in the public-facing web interface (/goform/wifiSSIDset) of the Tenda router, directly enabling T1190 (Exploit Public-Facing Application) for initial access and arbitrary code execution.

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

NVD Description

A flaw has been found in Tenda i12 1.0.0.11(3862). Affected by this vulnerability is the function formwrlSSIDset of the file /goform/wifiSSIDset of the component Parameter Handler. This manipulation of the argument index/wl_radio causes stack-based buffer overflow. It is possible to…

more

initiate the attack remotely. The exploit has been published and may be used.

Deeper analysisAI

CVE-2026-5609 is a stack-based buffer overflow vulnerability affecting the Tenda i12 router on firmware version 1.0.0.11(3862). The issue lies in the formwrlSSIDset function of the /goform/wifiSSIDset file within the Parameter Handler component, where manipulation of the index/wl_radio argument triggers the overflow. It is remotely exploitable and associated with CWE-119 and CWE-121, earning 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).

An attacker with low privileges can exploit this vulnerability remotely over the network with low complexity and without requiring user interaction. Successful exploitation enables high-impact compromise of confidentiality, integrity, and availability, potentially leading to arbitrary code execution or system crashes via the buffer overflow.

Advisories referenced in VulDB entries (vuln/355400 and related pages) document the flaw and its exploitability, while a GitHub repository provides a published proof-of-concept exploit. The vendor's site at tenda.com.cn is listed, but no specific patches or mitigation guidance is detailed in the available references.

An exploit has been publicly released, heightening the risk of real-world attacks against unpatched Tenda i12 devices.

Details

CWE(s)

Affected Products

tenda
i12 firmware
1.0.0.11\(3862\)

CVEs Like This One

CVE-2026-4043Same product: Tenda I12
CVE-2026-4042Same product: Tenda I12
CVE-2026-4041Same product: Tenda I12
CVE-2025-29149Same product: Tenda I12
CVE-2025-25676Same product: Tenda I12
CVE-2025-25678Same product: Tenda I12
CVE-2026-5849Same product: Tenda I12
CVE-2025-25679Same product: Tenda I12
CVE-2025-11324Same vendor: Tenda
CVE-2025-15006Same vendor: Tenda

References