{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-102715","assignerOrgId":"e51fbebd-6053-4e49-959f-1b94eeb69a2c","state":"PUBLISHED","assignerShortName":"eclipse","dateReserved":"2026-09-29T16:15:11.235Z","datePublished":"2026-09-29T17:42:35.719Z","dateUpdated":"2026-09-29T18:42:21.812Z"},"containers":{"cna":{"providerMetadata":{"orgId":"e51fbebd-6053-4e49-959f-1b94eeb69a2c","shortName":"eclipse","dateUpdated":"2026-09-29T17:42:35.719Z"},"title":"mDNS string-cache lookup matches on slot size, so a peer name aliases a shorter one and the response encoder writes past the packet","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-787","description":"CWE-787 Out-of-bounds Write","type":"CWE"}]}],"affected":[{"vendor":"Eclipse Foundation","product":"eclipse-threadx/netxduo","versions":[{"status":"affected","version":"0","lessThanOrEqual":"6.5.1","versionType":"semver"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"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 & 0xFFFFFFFC) + 8) & 0xFFFFFFFF;\n\n\n\n...\n\n\n\nlen = *((USHORT*)(p - 2)); /* slot size, not string length */\n\n\n\nif ((len == memory_len) && ... _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.","supportingMedia":[{"type":"text/html","base64":false,"value":"

Any host on the LAN can send two mDNS records and make the responder write past the end of its

transmit packet.

The string table stores each name in a slot rounded up to a multiple of four:

```c

/* addons/mdns/nxd_mdns.c:11436, 11443, 11447 */

memory_len = ((memory_len & 0xFFFFFFFC) + 8) & 0xFFFFFFFF;

...

len = *((USHORT*)(p - 2)); /* slot size, not string length */

if ((len == memory_len) && ... _nx_mdns_name_match(start, memory_ptr, memory_size) ...)

```

The lookup that decides whether an incoming name is already stored compares the rounded slot size,

so names of 12, 13, 14 and 15 characters share one bucket. A second name in the bucket is answered

with the pointer to the first, and the record then carries a string up to three bytes longer than

the length the caller accounted for. `_nx_mdns_packet_rr_add` (nxd_mdns.c:8911) sizes its only

bound check from that stale length, and `_nx_mdns_name_string_encode` writes the real string.

Two PTR records are enough, both ordinary mDNS responses to a `_http._tcp` query, with owner names

whose lengths fall in the same bucket:

```

==87491==ERROR: AddressSanitizer: heap-buffer-overflow

WRITE of size 1 at 0x611000000124 thread T5

#0 _nx_mdns_name_string_encode addons/mdns/nxd_mdns.c:13096
#1 _nx_mdns_packet_rr_add addons/mdns/nxd_mdns.c:8911

0x611000000124 is 0 bytes to the right of 228-byte region

```

The overflow is one to three bytes of attacker-influenced name data past `nx_packet_data_end`. In a

normal pool that lands in the next packet in the same pool rather than in a redzone, so the visible

effect is a corrupted neighbouring packet or a corrupted pool free list rather than a clean crash.

Compare the slot size against the stored string length before declaring a match, or keep the

string length in the slot header and return it to the caller so the encoder and the bound check

agree.

"}]}],"references":[{"url":"https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-2gf7-5224-5vrj"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"ADJACENT","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":7.1,"vectorString":"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"}}],"credits":[{"lang":"en","value":"L0stHeart","type":"reporter"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.5"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-29T18:41:47.412014Z","id":"CVE-2026-102715","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-09-29T18:42:21.812Z"}}]}}