Sources: National Vulnerability Database, CVE.org, CISA KEV, FIRST EPSS
CVE-2026-121606 Overview
A vulnerability has been found in Qihoo 360 D621-2, D603-2, D600-2, D619, D606-6 and D706 up to 6.4.9. Affected by this issue is the function verify_sign of the file fs2/bin/iscm of the component Firmware Signature Verification. Such manipulation of the argument sign leads to improper verification of cryptographic signature. The attack can be launched remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Critical Impact
Affected Products
- Qihoo: see the vendor advisory for the exact affected versions
Discovery Timeline
- 2026-11-04: CVE-2026-121606 published to the National Vulnerability Database by cna@vuldb.com
- 2026-11-04: last updated in the NVD database
Technical Details for CVE-2026-121606
Vulnerability Analysis
CVE-2026-121606 is a Security Vulnerability weakness (CWE-345, CWE-347) in Qihoo. Based on its CVSS vector, the flaw can be reached over the network, needs no login, and needs no user interaction.
With a CVSS base score of 9.3, apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Root Cause
The vendor description states: A vulnerability has been found in Qihoo 360 D621-2, D603-2, D600-2, D619, D606-6 and D706 up to 6.4.9. Affected by this issue is the function verify_sign of the file fs2/bin/iscm of the component Firmware Signature Verification. Such manipulation of the argument sign leads to improper verification of cryptographic signature. The attack can be launched remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Attack Vector
Based on the CVSS vector, the flaw can be reached over the network, needs no login, and needs no user interaction. Attack complexity is low complexity.
No exploitation in the wild is confirmed by CISA at the time of the last update. Check the references below for any vendor or researcher proof of concept.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/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
Detection Methods for CVE-2026-121606
Detection Strategies
- Inventory every instance of Qihoo and compare the running version with the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Run an authenticated vulnerability scan once your scanner ships a check for this CVE.
Monitoring Recommendations
- Forward Qihoo application, access and audit logs to your SIEM for retrospective hunting.
- Alert on new processes, configuration changes or outbound connections from the affected service.
- Track the vendor advisory and the CISA KEV catalog for changes in exploitation status.
How to Mitigate CVE-2026-121606
Immediate Actions Required
- Apply the fixed version of Qihoo named in the vendor advisory.
- Prioritize internet facing and business critical instances first.
- Rescan after the change to confirm the exposure is closed.
Patch Information
Use the fixed version listed in the vendor advisory for Qihoo.
Workarounds
- If patching must wait, restrict network access to the affected service and place it behind authentication or a web application firewall rule.
CWE References
Technical References
This entry is built directly from NVD, CISA KEV and EPSS data. Verify fixed versions in the vendor advisory before you deploy.
Frequently asked questions
Related CVEs
Insufficient verification of data authenticity in Azure Billing allows an unauthorized attacker to elevate privileges over a network.
SolarWinds Observability Self-Hosted was found to be affected by an unauthenticated remote code execution vulnerability due to the insufficient integrity checks. Installations configured in a non-default and non-secure configuration are affected.
The /v1/Plan service relies entirely on a shared global API token for full administrative management, allowing arbitrary creation of zero-cost network access plans.
Rack::Session is a session management implementation for Rack. From 2.0.0 to before 2.1.2, Rack::Session::Cookie incorrectly handles decryption failures when configured with secrets:. If cookie decryption fails, the implementation falls back to a default decoder instead of rejecting the cookie. This allows an unauthenticated attacker to supply a crafted session cookie that is accepted as valid session data without knowledge of any configured secret. Because this mechanism is used to load session state, an attacker can manipulate session contents and potentially gain unauthorized access. This vulnerability is fixed in 2.1.2.
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.3 and 9.1.1-alpha.4, an unauthenticated attacker can forge a Google authentication token with `alg: "none"` to log in as any user linked to a Google account, without knowing their credentials. All deployments with Google authentication enabled are affected. The fix in versions 8.6.3 and 9.1.1-alpha.4 hardcodes the expected `RS256` algorithm instead of trusting the JWT header, and replaces the Google adapter's custom key fetcher with `jwks-rsa` which rejects unknown key IDs. As a workaround, dsable Google authentication until upgrading is possible.
OpenClaw before 2026.4.10 contains an input validation vulnerability that allows external hook metadata to be enqueued as trusted system events. Attackers can supply malicious hook names to escalate untrusted input into higher-trust agent context.
Earn your free CTEM certification.
Learn to scope, prioritize, validate and mobilize fixes for CVEs like CVE-2026-121606 with a free CTEM certification.
Beginner / Practitioner / Program Leader
Explore certifications