CyberSecBulletin
CVE-2026-121609NVD status: Deferred

Whole Home Router M5: Use of Hard-coded Password

Published Updated By the CyberSecBulletin desk

CVE-2026-121609 is a critical-severity use of hard-coded password vulnerability in Whole Home Router M5 from Qihoo 360, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Whole Home Router M5 versions: 4.0.17.1566. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.5% 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. Check which version of Whole Home Router M5 you run against the affected versions below, and install the vendor's latest release.
  2. 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
Qihoo 360Whole Home Router M54.0.17.1566Not stated

Version data comes from the organisation that assigned the CVE. 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
ChangedThe attack can reach beyond the vulnerable component into other systems.
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:C/C:H/I:H/A:H. Scored by CNA (vuldb.com).

Scoring systemScoreSeverityScored by
CVSS 4.09.3CriticalCNA (vuldb.com)
CVSS 3.110.0CriticalCNA (vuldb.com)
CVSS 2.010.0HighCNA (vuldb.com)

Official description

A vulnerability was identified in Qihoo 360 Whole Home Router M5 4.0.17.1566. This issue affects the function Home of the file /etc/init.d/mpt of the component Boot Script. The manipulation leads to hard-coded credentials. Remote exploitation of the attack is possible. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure but did not respond in any way.

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

The underlying weakness: Use of Hard-coded Password

The product contains a hard-coded password, which it uses for its own inbound authentication or for outbound authentication to external components.

How developers prevent this class of flaw

  • For outbound authentication: store passwords outside of the code in a strongly-protected, encrypted configuration file or database that is protected from access by all outsiders, including other local users on the same system. Properly protect the key (CWE-320). If you cannot use encryption to protect the file, then make sure that the permissions are as restrictive as possible.
  • For inbound authentication: Rather than hard-code a default username and password for first time logins, utilize a first login mode that requires the user to enter a unique strong password.
  • Perform access control checks and limit which entities can access the feature that requires the hard-coded password. For example, a feature might only be enabled through the system console instead of through a network connection.

More Use of Hard-coded Password vulnerabilities (CWE-259)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use of Hard-coded Password vulnerabilities

Spotted an error? Tell us.