Stack-based Buffer OverflowWeakness · CWE-121

CVE-2026-12846

CRITICAL · 10.0 CVSS v3.1 Published 2026-06-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
GV-I/O Box 4E is a smart embedded device with 4 input and 4 relays output that can be controlled over Ethernet and RS-485. DVRSearch is a service running by default on the IOBox listening for UDP messages on port 10001. Any user on the network can send messages to this service and interact with it. Upon receiving a UDP message, the server reads at most 1460 bytes into a local buffer and a pointer to the buffer is stored in a global variable: #### Net Mask field stack overflow The following code is vulnerable to a stack overflow that is attacker-controlled: v6 = strlen(g_network_config->net_mask); memcpy(&reply_buf[184], g_network_config->net_mask, v6);

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Stack-based buffer overflow in the DVRSearch service on GV-I/O Box 4E. The service reads UDP messages (up to 1460 bytes) and copies the attacker-controlled net_mask field into a fixed buffer offset at reply_buf[184] using memcpy without bounds checking. Since the net_mask length is derived from attacker input, a maliciously long net_mask value overflows the stack buffer.

MitigationNetwork segmentation and firewall rules to restrict unauthorized network access to UDP port 10001. Apply vendor firmware update when available. Consider replacing or upgrading the device if EOL.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify GV-I/O Box 4E device on the network
    Check your network inventory or physically inspect connected hardware for the GV-I/O Box 4E model. If using network scanning tools, look for devices responding to DVRSearch service probes on UDP port 10001.
    Affected if The environment contains a GV-I/O Box 4E device.
  2. Verify DVRSearch service is active
    Scan the target device for open UDP port 10001 using a tool like nmap: nmap -sU -p 10001 <target-ip>. Alternatively, check the device documentation or management interface for DVRSearch service status.
    Affected if The DVRSearch service is running and UDP port 10001 is open on the device.
  3. Confirm network exposure of the service
    Review firewall rules and network segmentation to determine if UDP port 10001 is accessible from untrusted network segments. Check if the device is directly exposed to the internet or accessible from guest/VLAN networks.
    Affected if UDP port 10001 is reachable from network segments that contain untrusted or unauthorized users.
  4. Assess firmware version
    Access the device management interface or check the firmware version through the vendor-provided tools. Compare your installed firmware version against any available vendor release notes or security advisories.
    Affected if The device firmware is older than the vendor fix or no firmware update has been applied.

You are affected if you have a GV-I/O Box 4E with the DVRSearch service running and UDP port 10001 exposed to untrusted network segments.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Network segmentation and firewall rules to restrict unauthorized network access to UDP port 10001. Apply vendor firmware update when available. Consider replacing or upgrading the device if EOL.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-12846 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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