{"id":"CVE-2026-102758","aliases":["EUVD-2026-89113","GHSA-f95g-xc4w-mrcr","GHSA-qfqh-8mhg-fcvw"],"status":"published","title":"The `_nx_secure_x509_asn1_tlv_block_parse()` function parses ASN.1 TLV (tag-length-value) blocks...","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.\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.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"adp","from":"cve"},"epss":{"day":"2026-11-10","score":0.00173,"percentile":0.06817,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-126"],"published":"2026-09-29T17:26:44Z","modified":"2026-10-28T02:30:38Z","products":[{"vendor":"eclipse foundation","product":"netx duo"}],"references":[{"url":"https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-f95g-xc4w-mrcr","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-102758","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-qfqh-8mhg-fcvw"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102758.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-102758","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.\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.","status":"published","published":"2026-09-29T17:26:44.424Z","modified":"2026-09-30T20:42:39.497Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"adp"}],"cwes":["CWE-126"],"updated_at":"2026-11-02T13:38:54.394896Z"}],"euvd":[{"id":"EUVD-2026-89113","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.\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.","status":"published","published":"2026-09-29T17:26:44Z","modified":"2026-09-30T20:42:39Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T17:27:47.293232Z"}],"ghsa":[{"id":"GHSA-qfqh-8mhg-fcvw","title":"The `_nx_secure_x509_asn1_tlv_block_parse()` function parses ASN.1 TLV (tag-length-value) blocks...","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.\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.","status":"published","published":"2026-09-29T18:32:04Z","modified":"2026-09-30T21:33:01Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-126"],"updated_at":"2026-11-02T15:12:39.341866Z"}],"nvd":[{"id":"CVE-2026-102758","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.\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.","status":"published","published":"2026-09-29T18:17:13.047Z","modified":"2026-09-30T21:17:05.347Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-126"],"updated_at":"2026-11-02T14:12:52.413234Z"}],"osv":[{"id":"CVE-2026-102758","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.\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.","status":"published","published":"2026-09-29T17:26:44.424Z","modified":"2026-10-28T02:30:38.672192915Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-126"],"updated_at":"2026-11-02T15:44:53.83521Z"}]}}