# CVE-2026-8764: H3C Magic B3 aspForm UpdateWanParams buffer overflow

> Remote attackers can trigger a buffer overflow in the UpdateWanParams function of H3C Magic B3 routers, potentially leading to code execution or service disruption.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 May 2026
- **Updated:** 18 May 2026
- **Also known as:** GHSA-fgq5-p2r5-jrm5

## What is CVE-2026-8764?

CVE-2026-8764 is a high-severity memory corruption vulnerability in H3C Magic B3, published on 17 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

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.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-8764?


## How do I fix CVE-2026-8764?

No fix has been published for CVE-2026-8764 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8764 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8764 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-8764 and fix it if it is affected.

What it is: CVE-2026-8764 is a high-severity memory corruption vulnerability in H3C Magic B3, published on 17 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-8764 exists.

Affected product: H3C Magic B3. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-8764/ (Markdown: https://insights.sbomify.com/CVE-2026-8764/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8764
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8764
- OSV: https://osv.dev/vulnerability/CVE-2026-8764

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-8764/
Summaries are generated and may contain mistakes; the official description above is the record.