{"id":"CVE-2026-102714","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-102714","generatedAt":"2026-10-28T02:59:21.645Z","title":"Three outcomes follow, selected by bytes the attacker controls. **Zero length byte.** The walker subtracts zero and advances zero.","description":"`_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.","published":"2026-09-29T18:17:11.000Z","lastModified":"2026-09-29T19:17:20.000Z","status":"Awaiting Analysis","sourceIdentifier":"emo@eclipse.org","cvss":{"version":"4.0","score":7.1,"severity":"HIGH","vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-125","CWE-191","CWE-835","CWE-1287"],"affected":[],"epss":{"score":0.00153,"percentile":0.04388,"date":"2026-10-26","history":[{"date":"2026-09-30","score":0.00153,"percentile":0.03785}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-29T18:17:11.000Z","detail":{"score":"7.1","severity":"HIGH","publishedAt":"2026-09-29T18:17:10.617Z"},"summary":"New CVE, high severity (CVSS 7.1)."}],"references":[{"url":"https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-39p4-p83c-58hr","source":"emo@eclipse.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-102714","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}