{"id":"CVE-2026-102715","aliases":["EUVD-2026-89178","GHSA-2gf7-5224-5vrj","GHSA-rp9p-ggxc-p9xm"],"status":"published","title":"mDNS string cache accepts a shorter name as a match for a longer stored one, so the known-answer encoder writes past the transmit packet","description":"In Eclipse ThreadX NetX Duo versions up to and including 6.5.2.202603, the mDNS add-on's string cache accepts a shorter name as a match for a longer stored one. A host on the local link can send two mDNS records that make a device performing continuous service discovery write up to three bytes past its transmit packet, corrupting a neighbouring packet or the pool's free list, and misattribute discovered records.","severity":{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00312,"percentile":0.2436,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-697","CWE-787"],"published":"2026-09-29T17:42:35Z","modified":"2026-11-10T15:50:38Z","products":[{"vendor":"eclipse foundation","product":"eclipse threadx netx duo"}],"references":[{"url":"https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-2gf7-5224-5vrj","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-102715","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-rp9p-ggxc-p9xm"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102715.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-102715","title":"mDNS string cache accepts a shorter name as a match for a longer stored one, so the known-answer encoder writes past the transmit packet","description":"In Eclipse ThreadX NetX Duo versions up to and including 6.5.2.202603, the mDNS add-on's string cache accepts a shorter name as a match for a longer stored one. A host on the local link can send two mDNS records that make a device performing continuous service discovery write up to three bytes past its transmit packet, corrupting a neighbouring packet or the pool's free list, and misattribute discovered records.","status":"published","published":"2026-09-29T17:42:35.719Z","modified":"2026-11-10T15:50:38.472Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-787","CWE-697"],"updated_at":"2026-11-10T16:39:23.649176Z"}],"euvd":[{"id":"EUVD-2026-89178","description":"In Eclipse ThreadX NetX Duo versions up to and including 6.5.2.202603, the mDNS add-on's string cache accepts a shorter name as a match for a longer stored one. A host on the local link can send two mDNS records that make a device performing continuous service discovery write up to three bytes past its transmit packet, corrupting a neighbouring packet or the pool's free list, and misattribute discovered records.","status":"published","published":"2026-09-29T17:42:35Z","modified":"2026-11-10T15:50:38Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-10T16:21:32.397558Z"}],"ghsa":[{"id":"GHSA-rp9p-ggxc-p9xm","title":"Any host on the LAN can send two mDNS records and make the responder write past the end of its\n\n\n...","description":"Any host on the LAN can send two mDNS records and make the responder write past the end of its\n\n\n\ntransmit packet.\n\n\n\nThe string table stores each name in a slot rounded up to a multiple of four:\n\n\n\n```c\n\n\n\n/* addons/mdns/nxd_mdns.c:11436, 11443, 11447 */\n\n\n\nmemory_len = ((memory_len \u0026 0xFFFFFFFC) + 8) \u0026 0xFFFFFFFF;\n\n\n\n...\n\n\n\nlen = *((USHORT*)(p - 2));           /* slot size, not string length */\n\n\n\nif ((len == memory_len) \u0026\u0026 ... _nx_mdns_name_match(start, memory_ptr, memory_size) ...)\n\n\n\n```\n\n\n\nThe lookup that decides whether an incoming name is already stored compares the rounded slot size,\n\n\n\nso names of 12, 13, 14 and 15 characters share one bucket. A second name in the bucket is answered\n\n\n\nwith the pointer to the first, and the record then carries a string up to three bytes longer than\n\n\n\nthe length the caller accounted for. `_nx_mdns_packet_rr_add` (nxd_mdns.c:8911) sizes its only\n\n\n\nbound check from that stale length, and `_nx_mdns_name_string_encode` writes the real string.\n\n\n\nTwo PTR records are enough, both ordinary mDNS responses to a `_http._tcp` query, with owner names\n\n\n\nwhose lengths fall in the same bucket:\n\n\n\n```\n\n\n\n==87491==ERROR: AddressSanitizer: heap-buffer-overflow\n\n\n\nWRITE of size 1 at 0x611000000124 thread T5\n\n    #0 _nx_mdns_name_string_encode  addons/mdns/nxd_mdns.c:13096\n    #1 _nx_mdns_packet_rr_add       addons/mdns/nxd_mdns.c:8911\n\n\n0x611000000124 is 0 bytes to the right of 228-byte region\n\n\n\n```\n\n\n\nThe overflow is one to three bytes of attacker-influenced name data past `nx_packet_data_end`. In a\n\n\n\nnormal pool that lands in the next packet in the same pool rather than in a redzone, so the visible\n\n\n\neffect is a corrupted neighbouring packet or a corrupted pool free list rather than a clean crash.\n\n\n\nCompare the slot size against the stored string length before declaring a match, or keep the\n\n\n\nstring length in the slot header and return it to the caller so the encoder and the bound check\n\n\n\nagree.","status":"published","published":"2026-09-29T18:32:01Z","modified":"2026-11-04T15:32:05Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"cwes":["CWE-697","CWE-787"],"updated_at":"2026-11-04T15:52:08.140959Z"}],"nvd":[{"id":"CVE-2026-102715","description":"In Eclipse ThreadX NetX Duo versions up to and including 6.5.2.202603, the mDNS add-on's string cache accepts a shorter name as a match for a longer stored one. A host on the local link can send two mDNS records that make a device performing continuous service discovery write up to three bytes past its transmit packet, corrupting a neighbouring packet or the pool's free list, and misattribute discovered records.","status":"published","published":"2026-09-29T18:17:10.78Z","modified":"2026-11-04T14:17:19.013Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"}],"cwes":["CWE-697","CWE-787"],"updated_at":"2026-11-04T16:04:09.073238Z"}],"osv":[{"id":"CVE-2026-102715","title":"mDNS string cache accepts a shorter name as a match for a longer stored one, so the known-answer encoder writes past the transmit packet","description":"In Eclipse ThreadX NetX Duo versions up to and including 6.5.2.202603, the mDNS add-on's string cache accepts a shorter name as a match for a longer stored one. A host on the local link can send two mDNS records that make a device performing continuous service discovery write up to three bytes past its transmit packet, corrupting a neighbouring packet or the pool's free list, and misattribute discovered records.","status":"published","published":"2026-09-29T17:42:35.719Z","modified":"2026-11-11T02:48:40.340557072Z","cvss":[{"version":"4.0","score":7.1,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-697","CWE-787"],"updated_at":"2026-11-11T03:22:04.464623Z"}]}}