Cyber Resilience

CVE-2026-27650

RCE in Buffalo Wcr-1166Dhpl Firmware ≤ 1.01

Published
27 March 2026
Modified
31 March 2026
Patch / advisory
CVSS Score v4 8.6
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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 0.0092 57th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-27650 is a high-severity OS Command Injection (CWE-78) vulnerability in Buffalo Wcr-1166Dhpl Firmware. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 43% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

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-2026-27650 is an OS Command Injection vulnerability (CWE-78) present in BUFFALO Wi-Fi router products. Published on 2026-03-27, it carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), marking it as critical. Exploitation enables attackers to execute arbitrary OS commands on the affected products.

The vulnerability is exploitable remotely over the network with low attack complexity, requiring no authentication or privileges and no user interaction. Successful attacks maintain an unchanged scope while achieving high impacts on confidentiality, integrity, and availability, potentially allowing full device compromise such as data theft, modification, or denial of service.

Advisories detailing mitigations and patches are available from JVN at https://jvn.jp/en/jp/JVN83788689/ and Buffalo at https://www.buffalo.jp/news/detail/20260323-01.html.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

OS Command Injection vulnerability exists in BUFFALO Wi-Fi router products. If this vulnerability is exploited, an arbitrary OS command may be executed on the products.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
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.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-32669Same product: Buffalo Fs-M1266
CVE-2026-33366Same product: Buffalo Fs-M1266
CVE-2026-32678Same product: Buffalo Fs-M1266
CVE-2026-45777Same vendor: Buffalo
CVE-2023-49038Same vendor: Buffalo
CVE-2026-33280Same product: Buffalo Fs-M1266
CVE-2024-26023Same vendor: Buffalo
CVE-2023-45741Same vendor: Buffalo
CVE-2023-46681Same vendor: Buffalo
CVE-2024-0292Shared CWE-78

Affected Assets

buffalo
wcr-1166dhpl firmware
≤ 1.01
buffalo
wsr3600be4-kh firmware
≤ 6.02
buffalo
wsr3600be4p firmware
≤ 5.02
buffalo
wxr-1750dhp firmware
≤ 2.63
buffalo
wxr-1750dhp2 firmware
≤ 2.63
buffalo
wxr18000be10p firmware
≤ 5.03
buffalo
wxr-1900dhp firmware
≤ 2.53
buffalo
wxr-1900dhp2 firmware
≤ 2.62
buffalo
wxr-1900dhp3 firmware
≤ 2.66
buffalo
wxr-5950ax12 firmware
≤ 3.57
+36 more product configuration(s) — see NVD for full list

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)
  • V1.2.5
  • V1.2.8
  • V15.2.5

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover missing or incorrect command sanitization during development.

Input validation directly neutralizes or rejects special characters that would otherwise alter OS command structure.

Least privilege reduces the permissions available to any process that could be subverted by injected commands.

Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.

Secure engineering principles require proper neutralization of untrusted input before command construction.

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

PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.

PR.PS-02 partial match
prevents

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

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.

finds

Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.

References