CVE-2026-121609Qihoo 360 Whole Home Router M5 hard-coded password
CVE-2026-121609 is a hard-coded password in Qihoo 360 Whole Home Router M5, rated critical (9.3 on CVSS 4.0).
Why this priority: Critical, and reachable over the network without an account.
Published · Updated · NVD status: Deferred
What it is
A password is built into the product and is the same on every install. Credentials are built into the product, so anyone who knows them can sign in to every install.
How it is reached
An attacker can exploit it over the network, without an account, and nobody has to click anything.
What an attacker gains
A successful attack can read the data it protects, change data or behaviour and take it offline. In practice, this kind of flaw lets an attacker sign in with credentials the vendor shipped or stored unprotected. The damage can spread past the vulnerable component into others.
Is it being exploited?
CISA's SSVC assessment notes a public proof of concept. It can be exploited automatically, at scale. EPSS estimates a 0.50% chance of exploitation activity in the next 30 days, higher than 43% of scored CVEs.
What to do
- No fixed version is listed yet. Find every place Qihoo 360 Whole Home Router M5 runs, watch the references for a fix, and plan a replacement if it is no longer supported.
- While there is no fix, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
Description from NVD
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.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Network edge devices: VPNs, firewalls, routers and gateways. They sit between the internet and internal networks, so a flaw in one is often the first step into everything behind it.
- Credentials kept in code, configuration, images or firmware. The flaw sits between a stored secret and anyone who can read where it is kept.
Trust boundaries in play
- Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
- Isolation between components. The impact crosses out of the vulnerable component into others it should be isolated from.
- Between a stored secret and anyone who can read where it is kept. An attacker who crosses it can sign in with credentials the vendor shipped or stored unprotected.
Questions to answer about your own systems
- Where does Qihoo 360 Whole Home Router M5 run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.