# CVE-2026-102759: NetX Secure TLS accepts an empty application-data record without verifying its message authentication code.


- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 29 Sep 2026
- **Updated:** 29 Sep 2026
- **Also known as:** GHSA-m7j3-vh25-xc8p, GHSA-q2vr-5v2w-fjr2

## What is CVE-2026-102759?

CVE-2026-102759 is a medium-severity vulnerability in Eclipse Foundation NetX Duo, published on 29 Sep 2026. 

### Official description

NetX Secure TLS accepts an empty application-data record without verifying its message authentication code. In `_nx_secure_verify_mac`, a decrypted application record whose length equals the negotiated MAC size is treated as valid and returns success after advancing the receive sequence number. The received MAC is never generated or compared.

Empty TLS application-data records are legal, and are commonly emitted by TLS 1.0 implementations as a BEAST mitigation.

Weakness: CWE-354 (Improper Validation of Integrity Check Value)

## Which versions are affected by CVE-2026-102759?


## How do I fix CVE-2026-102759?

No fix has been published for CVE-2026-102759 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-102759 being exploited?

There is no known exploitation of CVE-2026-102759 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-102759 and fix it if it is affected.

What it is: CVE-2026-102759 is a medium-severity vulnerability in Eclipse Foundation NetX Duo, published on 29 Sep 2026. 
Exploitation: There is no known exploitation of CVE-2026-102759 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-2026-102759/ (Markdown: https://insights.sbomify.com/CVE-2026-102759/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-102759
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-102759
- OSV: https://osv.dev/vulnerability/CVE-2026-102759

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-102759/
Summaries are generated and may contain mistakes; the official description above is the record.