Security Resilience

CVE-2026-3803

Memory Safety in Tenda I3 Firmware 1.0.0.6\(2204\)

Public PoCMemory Safety
Published
09 March 2026
Modified
09 March 2026
Patch / advisory
View advisory
CVSS Score v4 7.4
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.010 64th percentile
Risk Priority 39 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). EPSS scores by FIRST (EPSS SIG), generated by Empirical Security. Risk Priority is our own derived reading, not an NVD score.

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 Compromise Infrastructure (T1584); ranked in the top 36% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

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

Vulnerability Data

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…

more

available and might be used.

CWE(s)
CWE-119CWE-121

Related Threats

MITRE ATT&CK Enterprise Techniques

T1584 Compromise Infrastructure Resource Development
Adversaries may compromise third-party infrastructure that can be used during targeting.
attack.mitre.org →
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1189 Drive-by Compromise Initial Access
Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-3802Same product: Tenda I3
CVE-2026-3804Same product: Tenda I3
CVE-2026-3801Same product: Tenda I3
CVE-2026-3799Same product: Tenda I3
CVE-2026-3971Same product: Tenda I3
CVE-2026-3970Same product: Tenda I3
CVE-2025-7793Same vendor: Tenda
CVE-2025-11387Same vendor: Tenda
CVE-2025-7529Same vendor: Tenda
CVE-2025-7548Same vendor: Tenda

Affected Assets

tenda
i3 firmware
1.0.0.6\(2204\)

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and analysis can discover stack-buffer overflows before deployment.

SI-10 Information Input Validation good match

Input validation directly stops untrusted data from exceeding stack buffer bounds.

SI-16 Memory Protection good match

Memory-protection mechanisms limit the ability to execute injected code after a stack overflow.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles require memory-safe design and coding that structurally avoids buffer-boundary violations.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
blocks

Secure-development practices directly prevent introduction of stack buffer overflows.

ID.RA-01 partial match
blocks

Vulnerability scanning can discover stack buffer overflows but does not prevent their introduction.

PR.PS-02 partial match
blocks

Patching eliminates known instances of the weakness after discovery.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development catches out-of-bounds accesses before release, covering most instances of the weakness.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248594 OL 8 must implement address space layout randomization (ASLR) to protect its memory from unauthorized code execution. blocks CWE-121
Oracle Linux 9 (1 rule)
  • V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. blocks CWE-121

References