CVE-2026-3974
Published: 12 March 2026
Summary
CVE-2026-3974 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 28.3th 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
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Validates the cmdinput argument in the HTTP handler to prevent stack-based buffer overflows from oversized or malformed inputs.
Implements memory protections like stack canaries, ASLR, and non-executable stacks to block exploitation of the stack buffer overflow even if invalid input is processed.
Remediates the specific buffer overflow vulnerability through timely application of vendor firmware patches or updates.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Stack-based buffer overflow in public-facing HTTP formexeCommand endpoint (PR:L) directly enables remote exploitation of the web application for arbitrary code execution and privilege escalation to full device control.
NVD Description
A vulnerability was identified in Tenda W3 1.0.0.3(2204). This vulnerability affects the function formexeCommand of the file /goform/exeCommand of the component HTTP Handler. Such manipulation of the argument cmdinput leads to stack-based buffer overflow. The attack may be performed from…
more
remote. The exploit is publicly available and might be used.
Deeper analysisAI
CVE-2026-3974 is a stack-based buffer overflow vulnerability affecting the Tenda W3 router on firmware version 1.0.0.3(2204). The issue resides in the formexeCommand function of the /goform/exeCommand file within the HTTP Handler component, where manipulation of the cmdinput argument triggers the overflow. It is associated with CWEs-119, CWE-121, and CWE-787, and carries a CVSS 3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).
Remote attackers with low privileges can exploit this vulnerability without user interaction. By sending crafted requests to the affected endpoint, they can trigger the buffer overflow, potentially achieving high confidentiality, integrity, and availability impacts, including arbitrary code execution on the device.
Advisories reference a publicly available exploit in a GitHub repository at https://github.com/Svigo-o/Tenda_vul/tree/main/tenda-w3-formexeCommand-cmdinput-buffer-overflow, with further details on VulDB at https://vuldb.com/?ctiid.350409, https://vuldb.com/?id.350409, and https://vuldb.com/?submit.769177. The vendor site https://www.tenda.com.cn/ is listed, though no specific patches or mitigations are detailed in the provided references.
Details
- CWE(s)