CyberSecBulletin
CVE-2026-33280NVD status: Analyzed

BUFFALO Wi-Fi router products: Hidden Functionality

Published Updated By the CyberSecBulletin desk

CVE-2026-33280 is a critical-severity hidden functionality vulnerability in BUFFALO Wi-Fi router products from Buffalo, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected BUFFALO Wi-Fi router products versions: See "References" section. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.39% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Wcr-1166dhpl Firmware to 1.01 or a later version.
  2. Update Wsr3600be4-kh Firmware to 6.02 or a later version.
  3. Update Wsr3600be4p Firmware to 5.02 or a later version.
  4. Read the advisory on buffalo.jp for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
BUFFALOBUFFALO Wi-Fi router productsSee "References" sectionNot stated
BuffaloWcr-1166dhpl Firmwarebefore 1.011.01
BuffaloWsr3600be4-kh Firmwarebefore 6.026.02
BuffaloWsr3600be4p Firmwarebefore 5.025.02
BuffaloWxr-1750dhp Firmwarebefore 2.632.63
BuffaloWxr-1750dhp2 Firmwarebefore 2.632.63
BuffaloWxr18000be10p Firmwarebefore 5.035.03
BuffaloWxr-1900dhp Firmwarebefore 2.532.53
BuffaloWxr-1900dhp2 Firmwarebefore 2.622.62
BuffaloWxr-1900dhp3 Firmwarebefore 2.662.66
BuffaloWxr-5950ax12 Firmwarebefore 3.573.57
BuffaloWxr-6000ax12b Firmwarebefore 3.573.57
BuffaloWxr-6000ax12p Firmwarebefore 3.573.57
BuffaloWxr-6000ax12s Firmwarebefore 3.573.57
BuffaloWzr-1166dhp Firmwarebefore 2.202.20
BuffaloWzr-1166dhp2 Firmwarebefore 2.202.20
BuffaloWzr-1750dhp Firmwarebefore 2.322.32
BuffaloWzr-1750dhp2 Firmwarebefore 2.332.33
BuffaloWzr-s1750dhp Firmwarebefore 2.342.34
BuffaloWrm-d2133hp Firmwarebefore 3.013.01
BuffaloWrm-d2133hs Firmwarebefore 3.013.01
BuffaloWtr-m2133hp Firmwarebefore 3.013.01
BuffaloWtr-m2133hs Firmwarebefore 3.013.01
BuffaloWem-1266 Firmwarebefore 2.872.87
BuffaloWem-1266wp Firmwarebefore 2.872.87

Version data comes from the organisation that assigned the CVE; 22 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.08.6HighCNA (jpcert.or.jp)
CVSS 3.19.8CriticalNVD
CVSS 3.07.2HighCNA (jpcert.or.jp)

Official description

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Hidden Functionality

The product contains functionality that is not documented, not part of the specification, and not accessible through an interface or command sequence that is obvious to the product's users or administrators.

How developers prevent this class of flaw

  • Always verify the integrity of the product that is being installed.

More Hidden Functionality vulnerabilities (CWE-912)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in BUFFALO Wi-Fi router products

All BUFFALO Wi-Fi router products vulnerabilities

Recent Hidden Functionality vulnerabilities

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