Cyber Resilience

CVE-2026-33280

Buffalo Wcr-1166Dhpl Firmware ≤ 1.01

Published
27 March 2026
Modified
31 March 2026
Patch / advisory
View 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:H/UI:N/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 0.0038 31th percentile
Risk Priority 30 floored blend · peak EPSS

Summary

CVE-2026-33280 is a high-severity Hidden Functionality (CWE-912) vulnerability in Buffalo Wcr-1166Dhpl Firmware. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Redundant Access (T1108); ranked at the 31th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to CM-2 (Baseline Configuration) and CM-7 (Least Functionality) — 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-2026-33280 is a hidden functionality vulnerability (CWE-912) present in BUFFALO Wi-Fi router products. Published on 2026-03-27, it allows attackers to access the product's debugging functionality, which may result in the execution of arbitrary OS commands. The issue 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), classifying it as critical due to its potential for severe impact.

A remote attacker with network access can exploit this vulnerability without authentication, privileges, or user interaction. Exploitation involves low complexity and leads to high confidentiality, integrity, and availability impacts, enabling full compromise of the affected router through arbitrary OS command execution.

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. Security practitioners should review these sources for specific firmware updates, configuration changes, or other remediation steps applicable to affected products.

EU & UK References

Vulnerability Data

Hidden functionality issue exists in BUFFALO Wi-Fi router products, which may allow an attacker to gain access to the product’s debugging functionality, resulting in the execution of arbitrary OS commands.

CWE(s)
CWE-912

Related Threats

MITRE ATT&CK Enterprise Techniques

T1108 Redundant Access Stealth
**This technique has been deprecated.
attack.mitre.org →
T1505 Server Software Component Persistence
Adversaries may abuse legitimate extensible development features of servers to establish persistent access to systems.
attack.mitre.org →
T1505.003 Web Shell Persistence
Adversaries may backdoor web servers with web shells to establish persistent access to systems.
attack.mitre.org →
T1554 Compromise Host Software Binary Persistence
Adversaries may modify host software binaries to establish persistent access to systems.
attack.mitre.org →
T1195 Supply Chain Compromise Initial Access
Adversaries may manipulate products or product delivery mechanisms prior to receipt by a final consumer for the purpose of data or system compromise.
attack.mitre.org →
T1195.002 Compromise Software Supply Chain Initial Access
Adversaries may manipulate application software prior to receipt by a final consumer for the purpose of data or system compromise.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-32678Same product: Buffalo Fs-M1266
CVE-2026-33366Same product: Buffalo Fs-M1266
CVE-2026-32669Same product: Buffalo Fs-M1266
CVE-2026-27650Same product: Buffalo Fs-M1266
CVE-2025-11673Shared CWE-912
CVE-2026-14812Shared CWE-912
CVE-2026-61515Shared CWE-912
CVE-2023-25183Shared CWE-912
CVE-2023-4467Shared CWE-912
CVE-2024-37994Shared CWE-912

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

Mitigating Controls (NIST 800-53 r5) AI

CM-2 Baseline Configuration good match

Maintaining and reviewing a documented baseline configuration allows comparison that reveals any functionality absent from the approved specification.

CM-7 Least Functionality good match

Least-functionality configuration explicitly prohibits or restricts any capability not required by the approved baseline, blocking hidden additions.

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation activities are designed to discover undocumented or unspecified functionality after it has been introduced.

SA-15 Development Process, Standards, and Tools partial match

Documented development processes and standards require all functionality to be specified and visible, structurally preventing undocumented hidden features.

SA-3 System Development Life Cycle partial match

An SDLC that incorporates security engineering principles mandates that all product functions be part of the approved specification.

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 full match
prevents

Secure SDLC practices directly prevent introduction of undocumented hidden functionality during development.

ID.RA-09 mostly match
prevents

Pre-acquisition integrity/authenticity checks can detect undocumented hidden functions in supplied software/hardware.

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 and acceptance can discover undocumented functionality before release.

A.8.32 Change management mostly match
prevents

Change management processes can catch unauthorized additions but do not inherently prevent hidden functionality from being introduced.

A.8.16 Monitoring activities partial match
finds

Monitoring activities can detect anomalous behavior from hidden functions but do not eliminate the weakness.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates documented requirements and design reviews that would expose undocumented hidden functionality.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly define expected functionality, making hidden features a violation.

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

Secure system architecture and engineering principles require transparent, documented designs that preclude hidden functionality.

References