Cyber Posture

CVE-2026-2874

HighPublic PoC

Published: 21 February 2026

Published
21 February 2026
Modified
23 February 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 29.3th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Description

A flaw has been found in Tenda A21 1.0.0.0. Impacted is the function form_fast_setting_wifi_set of the file /goform/fast_setting_wifi_set. Executing a manipulation of the argument ssid can lead to stack-based buffer overflow. It is possible to launch the attack remotely. The…

more

exploit has been published and may be used.

Mitigating Controls (NIST 800-53 r5)AI

prevent

Timely remediation through firmware patching directly eliminates the stack-based buffer overflow in the form_fast_setting_wifi_set function.

prevent

Validates the ssid argument to prevent the improper restriction of operations leading to stack-based buffer overflow.

prevent

Provides memory protections like stack canaries and ASLR to block exploitation of the stack-based buffer overflow vulnerability.

Security SummaryAI

CVE-2026-2874, published on 2026-02-21, is a stack-based buffer overflow vulnerability in Tenda A21 router firmware version 1.0.0.0. The flaw resides in the function form_fast_setting_wifi_set within the file /goform/fast_setting_wifi_set, where manipulation of the ssid argument triggers the overflow.

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) and maps to CWEs 119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and 121 (Stack-based Buffer Overflow). It can be exploited remotely by an attacker possessing low privileges, enabling high-impact consequences on confidentiality, integrity, and availability, such as potential arbitrary code execution.

Advisories and details are documented on VulDB (ctiid.347111, id.347111, submit.754636) and a GitHub repository (QIU-DIE/cve-nneeww/issues/5), where the exploit has been published and may be used. The vendor site is available at https://www.tenda.com.cn/.

The exploit's public availability heightens the risk for unpatched Tenda A21 devices exposed to the network.

Details

CWE(s)

Affected Products

tenda
a21 firmware
1.0.0.0

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 interface enables remote arbitrary code execution from low privileges, directly facilitating T1190 (Exploit Public-Facing Application) and T1068 (Exploitation for Privilege Escalation).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References