`_nx_icmpv6_validate_options()` scans the option area with `while (length > 2)` (`common/src/nx_icmpv6_validate_options.c:79`). An area whose size leaves a one- or two-byte residue exits the loop with that tail unexamined; the residue is not negative, so the function returns `NX_SUCCESS`. Its zero-length rejection never sees those bytes.
Every consumer then re-walks the same area, reading a two-byte option header at the residue and subtracting `nx_icmpv6_option_length << 3` with no zero check and no remaining-length check. Three outcomes follow, selected by bytes the attacker controls.
**Zero length byte.** The walker subtracts zero and advances zero. All four handlers loop forever — `_nx_icmpv6_process_ra` (`nx_icmpv6_process_ra.c:245, :528`), `_nx_icmpv6_process_ns` (`:251, :329`), `_nx_icmpv6_process_na` (`:147, :156`) and `_nx_icmpv6_process_redirect` (`:247, :350`). The walk runs in the IP thread, which is the highest-priority thread and does not yield inside the loop, so the system stops until a watchdog reset and the frame can be replayed after each one.
**Non-zero length byte on a short residue.** The three unsigned counters underflow — `2 - 8` becomes `0xFFFFFFFA` — and the walk continues past the packet buffer, reading until it faults or meets a zero length byte and freezes. The Router Advertisement counter is signed and exits cleanly in this case.
**One-byte residue.** The walker reads a two-byte option header, over-reading one byte.
During a runaway walk, stray bytes parsing as a link-layer address option are copied into the neighbor cache (`nx_icmpv6_process_ns.c:280, :293`) and subsequently used as the destination MAC for frames to that neighbour, placing off-packet memory on the link. Confirmed by inspection, not reproduced.
GHSA-jj75-gvv3-wr54
`_nx_icmpv6_validate_options()` scans the option area with `while (length > 2)` (`common/src...
https://github.com/advisories/GHSA-jj75-gvv3-wr54_nx_icmpv6_validate_options() scans the option area with while (length > 2) (common/src/nx_icmpv6_validate_options.c:79). An area whose size leaves a one- or two-byte residue exits the loop with that tail unexamined; the residue is not negative, so the function returns NX_SUCCESS. Its zero-length rejection never sees those bytes.
Every consumer then re-walks the same area, reading a two-byte option header at the residue and subtracting nx_icmpv6_option_length << 3 with no zero check and no remaining-length check. Three outcomes follow, selected by bytes the attacker controls.
Zero length byte. The walker subtracts zero and advances zero. All four handlers loop forever — _nx_icmpv6_process_ra (nx_icmpv6_process_ra.c:245, :528), _nx_icmpv6_process_ns (:251, :329), _nx_icmpv6_process_na (:147, :156) and _nx_icmpv6_process_redirect (:247, :350). The walk runs in the IP thread, which is the highest-priority thread and does not yield inside the loop, so the system stops until a watchdog reset and the frame can be replayed after each one.
Non-zero length byte on a short residue. The three unsigned counters underflow — 2 - 8 becomes 0xFFFFFFFA — and the walk continues past the packet buffer, reading until it faults or meets a zero length byte and freezes. The Router Advertisement counter is signed and exits cleanly in this case.
One-byte residue. The walker reads a two-byte option header, over-reading one byte.
During a runaway walk, stray bytes parsing as a link-layer address option are copied into the neighbor cache (nx_icmpv6_process_ns.c:280, :293) and subsequently used as the destination MAC for frames to that neighbour, placing off-packet memory on the link. Confirmed by inspection, not reproduced.
Click to expand
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"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-102714",
"assignerOrgId": "e51fbebd-6053-4e49-959f-1b94eeb69a2c",
"assignerShortName": "eclipse",
"dateUpdated": "2026-09-29T17:41:28.517Z",
"dateReserved": "2026-09-29T16:15:10.456Z",
"datePublished": "2026-09-29T17:41:28.517Z",
"state": "PUBLISHED"
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"value": "`_nx_icmpv6_validate_options()` scans the option area with `while (length > 2)` (`common/src/nx_icmpv6_validate_options.c:79`). An area whose size leaves a one- or two-byte residue exits the loop with that tail unexamined; the residue is not negative, so the function returns `NX_SUCCESS`. Its zero-length rejection never sees those bytes.\n\n\n\nEvery consumer then re-walks the same area, reading a two-byte option header at the residue and subtracting `nx_icmpv6_option_length << 3` with no zero check and no remaining-length check. Three outcomes follow, selected by bytes the attacker controls.\n\n\n\n**Zero length byte.** The walker subtracts zero and advances zero. All four handlers loop forever — `_nx_icmpv6_process_ra` (`nx_icmpv6_process_ra.c:245, :528`), `_nx_icmpv6_process_ns` (`:251, :329`), `_nx_icmpv6_process_na` (`:147, :156`) and `_nx_icmpv6_process_redirect` (`:247, :350`). The walk runs in the IP thread, which is the highest-priority thread and does not yield inside the loop, so the system stops until a watchdog reset and the frame can be replayed after each one.\n\n\n\n**Non-zero length byte on a short residue.** The three unsigned counters underflow — `2 - 8` becomes `0xFFFFFFFA` — and the walk continues past the packet buffer, reading until it faults or meets a zero length byte and freezes. The Router Advertisement counter is signed and exits cleanly in this case.\n\n\n\n**One-byte residue.** The walker reads a two-byte option header, over-reading one byte.\n\n\n\nDuring a runaway walk, stray bytes parsing as a link-layer address option are copied into the neighbor cache (`nx_icmpv6_process_ns.c:280, :293`) and subsequently used as the destination MAC for frames to that neighbour, placing off-packet memory on the link. Confirmed by inspection, not reproduced.",
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"value": "<p>`_nx_icmpv6_validate_options()` scans the option area with `while (length > 2)` (`common/src/nx_icmpv6_validate_options.c:79`). An area whose size leaves a one- or two-byte residue exits the loop with that tail unexamined; the residue is not negative, so the function returns `NX_SUCCESS`. Its zero-length rejection never sees those bytes.</p><p>Every consumer then re-walks the same area, reading a two-byte option header at the residue and subtracting `nx_icmpv6_option_length << 3` with no zero check and no remaining-length check. Three outcomes follow, selected by bytes the attacker controls.</p><p>**Zero length byte.** The walker subtracts zero and advances zero. All four handlers loop forever — `_nx_icmpv6_process_ra` (`nx_icmpv6_process_ra.c:245, :528`), `_nx_icmpv6_process_ns` (`:251, :329`), `_nx_icmpv6_process_na` (`:147, :156`) and `_nx_icmpv6_process_redirect` (`:247, :350`). The walk runs in the IP thread, which is the highest-priority thread and does not yield inside the loop, so the system stops until a watchdog reset and the frame can be replayed after each one.</p><p>**Non-zero length byte on a short residue.** The three unsigned counters underflow — `2 - 8` becomes `0xFFFFFFFA` — and the walk continues past the packet buffer, reading until it faults or meets a zero length byte and freezes. The Router Advertisement counter is signed and exits cleanly in this case.</p><p>**One-byte residue.** The walker reads a two-byte option header, over-reading one byte.</p><p>During a runaway walk, stray bytes parsing as a link-layer address option are copied into the neighbor cache (`nx_icmpv6_process_ns.c:280, :293`) and subsequently used as the destination MAC for frames to that neighbour, placing off-packet memory on the link. Confirmed by inspection, not reproduced.</p>"
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]
}
],
"affected": [
{
"vendor": "Eclipse Foundation",
"product": "NetX Duo",
"defaultStatus": "unaffected",
"versions": [
{
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"status": "affected",
"versionType": "semver",
"lessThanOrEqual": "6.5.1.202602"
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"descriptions": [
{
"lang": "en",
"description": "CWE-125 Out-of-bounds Read",
"cweId": "CWE-125",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"lang": "en",
"description": "CWE-191 Integer Underflow (Wrap or Wraparound)",
"cweId": "CWE-191",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"lang": "en",
"description": "CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')",
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"type": "CWE"
}
]
},
{
"descriptions": [
{
"lang": "en",
"description": "CWE-1287 Improper Validation of Specified Type of Input",
"cweId": "CWE-1287",
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]
}
],
"references": [
{
"url": "https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-39p4-p83c-58hr"
}
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