# CVE-2026-102761: Memory corruption in NetX Duo

> A memory corruption vulnerability in NetX Duo's WebSocket client allows attackers to execute arbitrary code or cause denial of service via crafted masked frames.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Sep 2026
- **Updated:** 30 Sep 2026
- **Also known as:** GHSA-6xgx-v7gw-qjph, GHSA-mjm4-7228-hgjf

## What is CVE-2026-102761?

CVE-2026-102761 is a critical memory corruption vulnerability in Eclipse Foundation NetX Duo, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

NetX Duo's WebSocket client resets the unmasking cursor to the first `NX_PACKET` each time it advances through a chained packet, while the loop's upper bound belongs to the current packet. With the standard contiguous packet-pool layout, a masked server frame split across two packets therefore drives the XOR loop through the first packet's unused payload area and on through the second packet's `NX_PACKET` control block.

The four-byte WebSocket masking key controls the bytes written, so the corruption is attacker-chosen rather than incidental.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-102761?


## How do I fix CVE-2026-102761?

No fix has been published for CVE-2026-102761 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-102761 being exploited?

There is no known exploitation of CVE-2026-102761 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-102761 and fix it if it is affected.

What it is: CVE-2026-102761 is a critical memory corruption vulnerability in Eclipse Foundation NetX Duo, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-102761 in the wild and no public exploit code.

Affected product: Eclipse Foundation NetX Duo. 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-2026-102761/ (Markdown: https://insights.sbomify.com/CVE-2026-102761/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-102761
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-102761
- OSV: https://osv.dev/vulnerability/CVE-2026-102761

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-102761/
Summaries are generated and may contain mistakes; the official description above is the record.