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CRITICAL severity

CVE-2026-121606 — D600-2

CRITICAL

CVE-2026-121606 is a critical-severity (CVSS 10) CWE-345 vulnerability in qihoo_360 d600-2. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

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…

Published
Updated
Affected
6 products
Patched
See advisory
Exploits
None indexed
Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs15th percentile — riskier than 15% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Description

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 Products

6 products · 6 configurations
Application
d600-2qihoo_360
all
Application
d603-2qihoo_360
all
Application
d606-6qihoo_360
all
Application
d619qihoo_360
all
Application
d621-2qihoo_360
all
Application
d706qihoo_360
all

Detection & mitigation playbook

Vendor / appliance

  1. Detect

    Inventory every qihoo_360 d600-2 deployment and check each version against the affected-products list above.

  2. Remediation status

    The records we use list no fixed version for CVE-2026-121606. Check the qihoo_360 d600-2 advisory for a patched release, and apply the workarounds below until you can upgrade.

  3. Mitigate without a patch

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

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.
O3 Security · Runtime Protection

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Detect and block the exploit chain at execution, on systems you cannot patch yet.

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CVE-2026-121606: D600-2 (Critical 10)