Cyber Resilience

CVE-2026-2203

Memory Safety in Tenda Ac8 Firmware 16.03.33.05

Public PoCMemory Safety
Published
09 February 2026
Modified
10 February 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 0.0062 47th percentile
Risk Priority 37 floored blend · peak EPSS

Summary

CVE-2026-2203 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Tenda Ac8 Firmware. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 47th 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 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-2026-2203 is a buffer overflow vulnerability affecting the Tenda AC8 router running firmware version 16.03.33.05. The flaw resides in an unknown functionality of the /goform/fast_setting_wifi_set file within the Embedded Httpd Service component. Manipulating the timeZone argument triggers the buffer overflow, as classified under CWE-119 and CWE-120. 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 was published on 2026-02-09.

The vulnerability enables remote exploitation by attackers with low privileges (PR:L), requiring network access but low complexity and no user interaction. Successful exploitation allows attackers to achieve high impacts on confidentiality, integrity, and availability, potentially leading to full compromise of the affected device.

Advisories and references, including those from VulDB (ctiid.344906, id.344906, submit.750226), document the issue but do not specify official patches or mitigations in the available details. A proof-of-concept exploit is publicly available on GitHub at repositories under SunnyYANGyaya/cuicuishark-sheep-fishIOT, including a dedicated markdown file and PoC section for the Tenda AC8 fast_setting_wifi_set timeZone manipulation.

In notable context, the published exploit increases the risk of real-world attacks on unpatched Tenda AC8 devices, particularly in IoT environments.

EU & UK References

Vulnerability Data

A flaw has been found in Tenda AC8 16.03.33.05. Affected by this vulnerability is an unknown functionality of the file /goform/fast_setting_wifi_set of the component Embedded Httpd Service. This manipulation of the argument timeZone causes buffer overflow. Remote exploitation of the…

more

attack is possible. The exploit has been published and may be used.

CWE(s)
CWE-119CWE-120

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
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.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
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 →
T1055 Process Injection Stealth
Adversaries may inject code into processes in order to evade process-based defenses as well as possibly elevate privileges.
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-2026-2202Same product: Tenda Ac8
CVE-2025-4368Same product: Tenda Ac8
CVE-2025-12618Same product: Tenda Ac8
CVE-2026-3044Same product: Tenda Ac8
CVE-2025-5798Same product: Tenda Ac8
CVE-2025-5799Same product: Tenda Ac8
CVE-2025-25668Same product: Tenda Ac8
CVE-2025-25667Same product: Tenda Ac8
CVE-2025-25510Same product: Tenda Ac8
CVE-2026-4254Same product: Tenda Ac8

Affected Assets

tenda
ac8 firmware
16.03.33.05

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V17.3.2
  • V5.2.1

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and analysis can find missing size checks before deployment.

SI-10 Information Input Validation good match

Input validation directly enforces size checks before buffer copies.

SA-8 Security and Privacy Engineering Principles partial match

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

SI-16 Memory Protection partial match

Memory protection restricts exploitation impact of buffer overflows without eliminating the underlying coding flaw.

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
prevents

Secure SDLC practices (bounds checking, safe APIs, reviews) directly prevent this class of flaw.

ID.RA-01 partial match
prevents

Vulnerability scanning and code analysis directly surface buffer-boundary flaws.

ID.RA-08 partial match
prevents

Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.

PR.AT-02 partial match
prevents

Developer training on secure coding reduces introduction of memory-buffer errors.

PR.PS-02 partial match
prevents

Patching replaces vulnerable code containing buffer-boundary defects.

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.8.28 Secure coding mostly match
prevents

Secure coding directly requires bounds-checked memory operations, addressing the root cause of CWE-120.

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.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify memory-safety rules, but do not prescribe implementation details.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.

References