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PatchSiren cyber security CVE debrief

CVE-2026-8764 Unknown Vendor CVE debrief

CVE-2026-8764 describes a buffer overflow in the UpdateWanParams function exposed through /goform/aspForm on H3C Magic B3 devices up to 100R002. The issue is described as remotely reachable and publicly disclosed, which raises the urgency for anyone running the affected firmware range. The NVD record was published on 2026-05-17 and lists the issue as High severity.

Vendor
Unknown Vendor
Product
Unknown
CVSS
HIGH 7.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-17
Original CVE updated
2026-05-18
Advisory published
2026-05-17
Advisory updated
2026-05-18

Who should care

Administrators and security teams responsible for H3C Magic B3 devices, especially if the management or WAN configuration interface is reachable from untrusted networks. Network defenders, incident responders, and asset owners should also treat this as a priority if they cannot quickly confirm firmware exposure.

Technical summary

The CVE source describes a parameter-manipulation flaw in UpdateWanParams within /goform/aspForm that can trigger a buffer overflow. NVD maps the weakness to CWE-119 and CWE-120 and assigns CVSS v4.0 7.3/High with a network attack vector. The supplied description says the exploit was publicly disclosed and that the vendor was contacted early without response.

Defensive priority

High

Recommended defensive actions

  • Identify all H3C Magic B3 devices and confirm whether any run firmware up to 100R002.
  • Restrict access to the device management and WAN configuration interfaces from untrusted networks.
  • Apply a vendor-provided fix or firmware update if one becomes available; if none exists, plan compensating controls or replacement.
  • Monitor device logs and network telemetry for abnormal requests to /goform/aspForm and related management endpoints.
  • If exposure cannot be reduced quickly, isolate the device segment and treat it as a potential incident-response priority.

Evidence notes

The debrief is based on the CVE description and the NVD record published on 2026-05-17. The supplied source metadata includes references to a GitHub issue, a VulDB submission page, a VulDB vulnerability entry, and a VulDB CTI page. NVD lists the weaknesses as CWE-119 and CWE-120 and provides CVSS v4.0 7.3/High. The source description explicitly states that the exploit was publicly disclosed and that the vendor did not respond to early contact.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-8764 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-8764

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-8764 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-8764

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.