CVE-2026-6581Public exploitNetwork attack vector

Authenticated code execution via unchecked param copy

Published Apr 19, 2026 · Updated Apr 19, 2026

Buffer overflow in H3C Magic B1 100R004 and earlier allows remote authenticated users to execute code via a crafted param field. The SetMobileAPInfoById handler at /goform/aspForm copies the param value without a length limit, overflowing its destination buffer. Low-privileged access to the router's web interface is required; exploitation can crash the device or run code in the firmware context.

CVSS severity8.8
High
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in H3C Magic B1 100R004 and earlier allows remote authenticated users to execute code via a crafted param field. The SetMobileAPInfoById handler at /goform/aspForm copies the param value without a length limit, overflowing its destination buffer. Low-privileged access to the router's web interface is required; exploitation can crash the device or run code in the firmware context.

The record

CVE
CVE-2026-6581
Published
Apr 19, 2026
Updated
Apr 19, 2026
Vendor
New H3C Technologies Co., Ltd.
Product
H3C Magic B1
Classifications
CWE-119, CWE-120, CAPEC-100
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=100R004

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

New H3C Technologies Co., Ltd. · H3C Magic B1version=100R004

Published CVSS scores

8.8VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0VulDBAV:N/AC:L/Au:S/C:C/I:C/A:C
7.4VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CAPEC-100Overflow Buffers

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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