Cyber Resilience

CVE-2026-6581

High

Published: 19 April 2026

Published
19 April 2026
Modified
22 April 2026
KEV Added
Patch
CVSS Score v4 7.4 CVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0044 35.4th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-6581 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 35.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).

Deeper analysis

CVE-2026-6581 is a buffer overflow vulnerability affecting H3C Magic B1 devices up to version 100R004. The issue resides in the SetMobileAPInfoById function within the /goform/aspForm file, where manipulation of the "param" argument triggers the overflow. Classified under CWE-119 and CWE-120, it carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) and was published on 2026-04-19.

The vulnerability enables remote exploitation by attackers with low privileges (PR:L) over the network with low complexity and no user interaction required. Successful exploitation grants high-impact access to confidentiality, integrity, and availability, potentially allowing arbitrary code execution or system compromise on affected devices.

Advisories from VulDB indicate that the vendor was contacted early but provided no response, with no patches or mitigations disclosed. An exploit is publicly available, including details on GitHub at https://github.com/hmKunlun/H3Cc/blob/main/h3c.md and VulDB entries at https://vuldb.com/vuln/358216.

In notable context, the public exploit availability increases the risk of active misuse against unpatched H3C Magic B1 deployments.

EU & UK References

Vulnerability details

A vulnerability was detected in H3C Magic B1 up to 100R004. Affected by this vulnerability is the function SetMobileAPInfoById of the file /goform/aspForm. Performing a manipulation of the argument param results in buffer overflow. Remote exploitation of the attack is…

more

possible. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Buffer overflow in the web management interface (/goform/aspForm) of a network device directly enables remote exploitation of a public-facing application (T1190) for arbitrary code execution.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-6630Shared CWE-119, CWE-120
CVE-2026-7055Shared CWE-119, CWE-120
CVE-2026-1162Shared CWE-119, CWE-120
CVE-2025-12232Shared CWE-119, CWE-120
CVE-2025-15459Shared CWE-119, CWE-120
CVE-2025-7463Shared CWE-119, CWE-120
CVE-2026-2202Shared CWE-119, CWE-120
CVE-2026-5980Shared CWE-119, CWE-120
CVE-2026-7857Shared CWE-119, CWE-120
CVE-2026-7057Shared CWE-119, CWE-120

Affected Assets

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly prevents buffer overflow by enforcing input validation on the 'param' argument at web form entry points like /goform/aspForm.

prevent

Implements memory protections such as ASLR and non-executable memory to block arbitrary code execution from buffer overflow exploitation.

prevent

Requires timely remediation of known flaws like this buffer overflow vulnerability through patching or compensatory controls on affected H3C devices.

References