# CVE-2026-102758: Memory corruption in NetX Duo

> A buffer over-read in NetX Duo's ASN.1 parser allows remote attackers to cause a denial of service via crafted TLS certificates.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **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-f95g-xc4w-mrcr, GHSA-qfqh-8mhg-fcvw

## What is CVE-2026-102758?

CVE-2026-102758 is a high-severity 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

The `_nx_secure_x509_asn1_tlv_block_parse()` function parses ASN.1 TLV (tag-length-value) blocks out of DER-encoded data. It is the primitive underneath all X.509 certificate parsing in NetX Secure, and therefore runs on certificates supplied by a remote peer during the TLS handshake.

The function reads the one-byte ASN.1 tag from the caller's buffer *before* checking that the buffer holds at least one byte. When a caller passes a remaining length of zero, the guard correctly returns `NX_SECURE_X509_ASN1_LENGTH_TOO_LONG`, but the read has already happened one byte past the end of the buffer.

code:

nx_secure/src/nx_secure_x509_asn1_tlv_block_parse.c

```

UINT _nx_secure_x509_asn1_tlv_block_parse(const UCHAR *buffer, ULONG *buffer_length, USHORT *tlv_type,

                                          USHORT *tlv_tag_class, ULONG *tlv_length,
                                          const UCHAR **tlv_data, ULONG *header_length)

{

UINT   current_index;

USHORT current_tag;

ULONG  length;

ULONG  length_bytes;

    current_index = 0;
    current_tag = buffer[current_index];      /* <-- read before the bounds check */
    if (*buffer_length < 1)
    {
        return(NX_SECURE_X509_ASN1_LENGTH_TOO_LONG);
    }

```

The remainder of the function is correctly ordered. The multi-byte length path is guarded by `length_bytes > 4 || length_bytes > *buffer_length` before its read loop, the decoded value is checked against `length > *buffer_length`, and the second single-byte length read follows its own `*buffer_length < 1` guard. The tag read is the only load placed ahead of its check.

Weakness: CWE-126 (Buffer Over-read)

## Which versions are affected by CVE-2026-102758?


## How do I fix CVE-2026-102758?

No fix has been published for CVE-2026-102758 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-102758 being exploited?

There is no known exploitation of CVE-2026-102758 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-102758 and fix it if it is affected.

What it is: CVE-2026-102758 is a high-severity 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-2026-102758 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-2026-102758/ (Markdown: https://insights.sbomify.com/CVE-2026-102758/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-102758
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-102758
- OSV: https://osv.dev/vulnerability/CVE-2026-102758

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-102758/
Summaries are generated and may contain mistakes; the official description above is the record.