CVE-2026-3803
Published: 09 March 2026
Summary
CVE-2026-3803 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Tenda I3 Firmware. Its CVSS base score is 7.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 45.6th 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).
Deeper analysis
CVE-2026-3803 is a stack-based buffer overflow vulnerability affecting the Tenda i3 router on firmware version 1.0.0.6(2204). The flaw exists in the formWifiMacFilterGet function, processed via the /goform/WifiMacFilterGet endpoint, where manipulation of the index argument triggers the overflow. Published on 2026-03-09, it is associated with CWE-119 and CWE-121.
Attackers can exploit this remotely over the network with low complexity and low privileges (PR:L), requiring no user interaction. The CVSS v3.1 score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) reflects high impacts on confidentiality, integrity, and availability, potentially enabling arbitrary code execution on the affected device.
References include a public exploit on GitHub (https://github.com/Svigo-o/Tenda_vul/tree/main/tenda-i3-formWifiMacFilterGet-index-buffer-overflow) and VulDB advisories (https://vuldb.com/?ctiid.349770, https://vuldb.com/?id.349770, https://vuldb.com/?submit.768984), with the vendor site at https://www.tenda.com.cn/. The exploit is publicly available and might be used, but no specific mitigation or patch details are provided in the references.
The vulnerability carries notable risk due to the public exploit availability, increasing the likelihood of real-world abuse against exposed Tenda i3 devices.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-10297
Vulnerability details
A vulnerability was identified in Tenda i3 1.0.0.6(2204). This affects the function formWifiMacFilterGet of the file /goform/WifiMacFilterGet. The manipulation of the argument index leads to stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit is publicly…
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available and might be used.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Stack-based buffer overflow in public web management endpoint (/goform/WifiMacFilterGet) on network device allows remote unauthenticated/low-priv RCE, directly mapping to exploitation of public-facing applications.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly prevents stack-based buffer overflow by validating the manipulated 'index' argument in the formWifiMacFilterGet function.
Mitigates stack-based buffer overflow exploitation through memory protection mechanisms like stack canaries and address space randomization.
Addresses the vulnerability comprehensively by remediating the specific flaw in the Tenda i3 firmware via timely patching.