---
id: CVE-2026-121606
title: >-
  Qihoo 360 D621-2/D603-2/D600-2/D619/D606-6/D706 Firmware Signature
  Verification iscm verify_sign signature verification
summary: >-
  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 man…
severity: critical
cvss: 10
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:C'
cvssSource: cna
cwe:
  - CWE-347
  - CWE-345
vendor: Qihoo 360
product: D621-2
affected:
  - D621-2 6.4.0
  - D621-2 6.4.1
  - D621-2 6.4.2
  - D621-2 6.4.3
  - D621-2 6.4.4
  - D621-2 6.4.5
  - D621-2 6.4.6
  - D621-2 6.4.7
  - D621-2 6.4.8
  - D621-2 6.4.9
  - D603-2 6.4.0
  - D603-2 6.4.1
  - D603-2 6.4.2
  - D603-2 6.4.3
  - D603-2 6.4.4
  - D603-2 6.4.5
  - D603-2 6.4.6
  - D603-2 6.4.7
  - D603-2 6.4.8
  - D603-2 6.4.9
  - D600-2 6.4.0
  - D600-2 6.4.1
  - D600-2 6.4.2
  - D600-2 6.4.3
  - D600-2 6.4.4
  - D600-2 6.4.5
  - D600-2 6.4.6
  - D600-2 6.4.7
  - D600-2 6.4.8
  - D600-2 6.4.9
  - D619 6.4.0
  - D619 6.4.1
  - D619 6.4.2
  - D619 6.4.3
  - D619 6.4.4
  - D619 6.4.5
  - D619 6.4.6
  - D619 6.4.7
  - D619 6.4.8
  - D619 6.4.9
  - D606-6 6.4.0
  - D606-6 6.4.1
  - D606-6 6.4.2
  - D606-6 6.4.3
  - D606-6 6.4.4
  - D606-6 6.4.5
  - D606-6 6.4.6
  - D606-6 6.4.7
  - D606-6 6.4.8
  - D606-6 6.4.9
published: '2026-11-04'
updated: '2026-11-04'
sourceUpdated: '2026-11-04T01:00:26.282Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-121606'
references:
  - url: 'https://vuldb.com/vuln/430443'
    label: >-
      VDB-430443 | Qihoo 360 D621-2/D603-2/D600-2/D619/D606-6/D706 Firmware
      Signature Verification iscm verify_sign signature verification
  - url: 'https://vuldb.com/vuln/430443/cti'
    label: 'VDB-430443 | CTI Indicators (IOB, IOC, IOA)'
  - url: 'https://vuldb.com/cve/CVE-2026-121606'
    label: CVE-2026-121606 | CVE Analysis and Report
  - url: 'https://vuldb.com/submit/1023261'
    label: >-
      Submit #1023261 | 360 (Qihoo 360) 360 Smart Camera (IPC) 6.0.24 ~ 6.4.9
      Improper Verification of Cryptographic Signature
  - url: 'https://gist.github.com/gajgdm6-cpu/cf98af20ddb77f27a7c112214a6280f7'
tags:
  - cve.org
epss: 0.0024
epssPercentile: 0.15169
ingestedAt: '2026-11-05T20:33:06.654Z'
---

## 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.

## Affected

- `D621-2 6.4.0`
- `D621-2 6.4.1`
- `D621-2 6.4.2`
- `D621-2 6.4.3`
- `D621-2 6.4.4`
- `D621-2 6.4.5`
- `D621-2 6.4.6`
- `D621-2 6.4.7`
- `D621-2 6.4.8`
- `D621-2 6.4.9`
- `D603-2 6.4.0`
- `D603-2 6.4.1`
- `D603-2 6.4.2`
- `D603-2 6.4.3`
- `D603-2 6.4.4`
- `D603-2 6.4.5`
- `D603-2 6.4.6`
- `D603-2 6.4.7`
- `D603-2 6.4.8`
- `D603-2 6.4.9`
- `D600-2 6.4.0`
- `D600-2 6.4.1`
- `D600-2 6.4.2`
- `D600-2 6.4.3`
- `D600-2 6.4.4`
- `D600-2 6.4.5`
- `D600-2 6.4.6`
- `D600-2 6.4.7`
- `D600-2 6.4.8`
- `D600-2 6.4.9`
- `D619 6.4.0`
- `D619 6.4.1`
- `D619 6.4.2`
- `D619 6.4.3`
- `D619 6.4.4`
- `D619 6.4.5`
- `D619 6.4.6`
- `D619 6.4.7`
- `D619 6.4.8`
- `D619 6.4.9`
- `D606-6 6.4.0`
- `D606-6 6.4.1`
- `D606-6 6.4.2`
- `D606-6 6.4.3`
- `D606-6 6.4.4`
- `D606-6 6.4.5`
- `D606-6 6.4.6`
- `D606-6 6.4.7`
- `D606-6 6.4.8`
- `D606-6 6.4.9`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.