Memory Buffer Bounds ErrorWeakness · CWE-119

CVE-2026-8764

HIGH · 7.2 CVSS v3.1 Published 2026-05-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
78/100
Remediation priority · High
Remotely reachable Zero-click

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
A security vulnerability has been detected in H3C Magic B3 up to 100R002. This affects the function UpdateWanParams of the file /goform/aspForm. Such manipulation of the argument param leads to buffer overflow. The attack may be performed from remote. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

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 · moderate confidence

Buffer overflow vulnerability in H3C Magic B3 routers (firmware 100R002 and earlier) in the UpdateWanParams function of /goform/aspForm web interface. Remote attackers can exploit this by manipulating the 'param' argument to overflow a buffer, potentially leading to code execution or denial of service.

MitigationSince the vendor has not responded to the disclosure, implement network segmentation to isolate the affected device, restrict access to the web management interface via firewall rules, and monitor for indicators of compromise until a vendor patch becomes available.

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
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/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 the device model
    Access the router web interface or check the device label to confirm it is an H3C Magic B3 router. Alternatively, check the DHCP client list or network scan results for the device manufacturer and model identifier.
    Affected if The device is not an H3C Magic B3 router, then this specific CVE does not apply.
  2. Check the firmware version
    Log into the router web interface and navigate to the status or system settings page to view the firmware version. Alternatively, check the administrative GUI for a version display or use the router's diagnostic page if available.
    Affected if The firmware version is 100R002 or any version earlier than 100R002.
  3. Verify the web management interface is exposed
    Confirm that the router web interface at /goform/aspForm is accessible from the network. Attempt to access the URL or use a tool to check if the endpoint responds. The vulnerability exists in the UpdateWanParams function within this web interface.
    Affected if The /goform/aspForm web interface is accessible from the network and responds to requests.
  4. Check for WAN parameter configuration access
    Locate the WAN settings or internet connection configuration section in the router web interface. The vulnerable UpdateWanParams function processes the 'param' argument related to WAN parameters.
    Affected if WAN parameter configuration is available and can be modified through the web interface.

A user is affected if they are running an H3C Magic B3 router with firmware version 100R002 or earlier and the web management interface is accessible on their network.

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

Since the vendor has not responded to the disclosure, implement network segmentation to isolate the affected device, restrict access to the web management interface via firewall rules, and monitor for indicators of compromise until a vendor patch becomes available.

Have this fixed Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
36.0 hours of engineering $6,400
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Scan for this in your stack

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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-2026-8764 in production — separate from our analysis above.

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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
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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