{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "6.5.1.202602"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "1a0e9e43a03e37ddecfb6b49e9b078d6e1803d05"
            }
          ],
          "repo": "https://github.com/eclipse-threadx/netxduo",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-f95g-xc4w-mrcr"
  ],
  "database_specific": {
    "cna_assigner": "eclipse",
    "cwe_ids": [
      "CWE-126"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102758.json"
  },
  "details": "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.\n\n\n\nThe 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.\n\n\n\ncode:\n\n\n\nnx_secure/src/nx_secure_x509_asn1_tlv_block_parse.c\n\n\n\n```\n\n\n\nUINT _nx_secure_x509_asn1_tlv_block_parse(const UCHAR *buffer, ULONG *buffer_length, USHORT *tlv_type,\n\n                                          USHORT *tlv_tag_class, ULONG *tlv_length,\n                                          const UCHAR **tlv_data, ULONG *header_length)\n\n\n{\n\n\n\nUINT   current_index;\n\n\n\nUSHORT current_tag;\n\n\n\nULONG  length;\n\n\n\nULONG  length_bytes;\n\n    current_index = 0;\n    current_tag = buffer[current_index];      /* \u003c-- read before the bounds check */\n    if (*buffer_length \u003c 1)\n    {\n        return(NX_SECURE_X509_ASN1_LENGTH_TOO_LONG);\n    }\n\n\n```\n\n\n\nThe remainder of the function is correctly ordered. The multi-byte length path is guarded by `length_bytes \u003e 4 || length_bytes \u003e *buffer_length` before its read loop, the decoded value is checked against `length \u003e *buffer_length`, and the second single-byte length read follows its own `*buffer_length \u003c 1` guard. The tag read is the only load placed ahead of its check.",
  "id": "CVE-2026-102758",
  "modified": "2026-10-02T03:31:00.498125350Z",
  "published": "2026-09-29T17:26:44.424Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102758.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-f95g-xc4w-mrcr"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-102758"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}