{"id":"CVE-2026-12630","state":"PUBLISHED","title":"6LoWPAN IPHC uncompression out-of-bounds read on reserved destination addressing mode","description":"Zephyr's 6LoWPAN IP Header Compression (IPHC) uncompression code contains an out-of-bounds read in get_ihpc_inlined_size() (subsys/net/ip/6lo.c). The destination inline size is looked up in da_inline_size_table, which has 13 entries, using an index built from the M, DAC and DAM bits of the received IPHC dispatch word (iphc & NET_6LO_IPHC_DA_MASK, a 4-bit value of 0-15). The reserved combinations 13, 14 and 15 are not bounds-checked and read past the end of the table.\n\nThe iphc word is taken directly from the received frame, and get_ihpc_inlined_size() is reached on every inbound 6LoWPAN frame via net_6lo_uncompress() from the 802.15.4 receive path (subsys/net/l2/ieee802154/ieee802154_6lo.c and ieee802154_6lo_fragment.c). An unauthenticated attacker on the radio/adjacent link can therefore craft a frame whose destination addressing-mode nibble selects an out-of-range index, with no privileges or user interaction.\n\nThe out-of-bounds value becomes the computed inline_size, which then drives header reconstruction before the buffer-length check: it is used to dereference *(pkt->buffer->data + sizeof(iphc) + inline_size) and to compute a size_t diff that can underflow, leading to a further out-of-bounds read of the packet buffer and malformed uncompression. The practical impact is a radio-triggerable out-of-bounds read / denial-of-service on the receiver; the leaked byte is not returned to the attacker. The fix rejects any destination index beyond the table, aborting processing of the malformed frame.","publishedAt":"2026-08-17T16:18:51.419Z","updatedAt":"2026-08-17T18:26:16.046Z","severity":{"score":4.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","source":"zephyr"},"assigner":"zephyr","products":["zephyrproject zephyr"],"affected":[{"vendor":"zephyrproject","product":"zephyr","packageName":"zephyr","defaultStatus":"unaffected","versions":[{"version":"2.0.0","status":"affected","lessThan":"4.4.2","versionType":"semver"}],"collectionURL":"https://github.com/zephyrproject-rtos/zephyr","programFiles":["subsys/net/ip/6lo.c"]}],"references":["https://github.com/zephyrproject-rtos/zephyr/commit/1bbb7aefa69eaedc22281ce33aa7a2d5089d5a0e","https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-45c8-pmgj-6jrc"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:10:52.580Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/12xxx/CVE-2026-12630.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-12630","state":"PUBLISHED","datePublished":"2026-08-17T16:18:51.419Z","dateUpdated":"2026-08-17T18:26:16.046Z","assignerShortName":"zephyr","assignerOrgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","dateReserved":"2026-06-18T15:22:25.574Z"},"containers":{"cna":{"title":"6LoWPAN IPHC uncompression out-of-bounds read on reserved destination addressing mode","descriptions":[{"lang":"en","value":"Zephyr's 6LoWPAN IP Header Compression (IPHC) uncompression code contains an out-of-bounds read in get_ihpc_inlined_size() (subsys/net/ip/6lo.c). The destination inline size is looked up in da_inline_size_table, which has 13 entries, using an index built from the M, DAC and DAM bits of the received IPHC dispatch word (iphc & NET_6LO_IPHC_DA_MASK, a 4-bit value of 0-15). The reserved combinations 13, 14 and 15 are not bounds-checked and read past the end of the table.\n\nThe iphc word is taken directly from the received frame, and get_ihpc_inlined_size() is reached on every inbound 6LoWPAN frame via net_6lo_uncompress() from the 802.15.4 receive path (subsys/net/l2/ieee802154/ieee802154_6lo.c and ieee802154_6lo_fragment.c). An unauthenticated attacker on the radio/adjacent link can therefore craft a frame whose destination addressing-mode nibble selects an out-of-range index, with no privileges or user interaction.\n\nThe out-of-bounds value becomes the computed inline_size, which then drives header reconstruction before the buffer-length check: it is used to dereference *(pkt->buffer->data + sizeof(iphc) + inline_size) and to compute a size_t diff that can underflow, leading to a further out-of-bounds read of the packet buffer and malformed uncompression. The practical impact is a radio-triggerable out-of-bounds read / denial-of-service on the receiver; the leaked byte is not returned to the attacker. The fix rejects any destination index beyond the table, aborting processing of the malformed frame."}],"affected":[{"vendor":"zephyrproject","product":"zephyr","packageName":"zephyr","defaultStatus":"unaffected","versions":[{"version":"2.0.0","status":"affected","lessThan":"4.4.2","versionType":"semver"}],"collectionURL":"https://github.com/zephyrproject-rtos/zephyr","programFiles":["subsys/net/ip/6lo.c"]}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/1bbb7aefa69eaedc22281ce33aa7a2d5089d5a0e","name":"Fix commit","tags":["patch"]},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-45c8-pmgj-6jrc","name":"GHSA-45c8-pmgj-6jrc"}],"metrics":[{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","baseScore":4.3,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","description":"bounds","type":"CWE"}]}],"providerMetadata":{"shortName":"zephyr","orgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","dateUpdated":"2026-08-17T16:18:51.419Z"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-17T18:25:42.464908Z","id":"CVE-2026-12630","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-17T18:26:16.046Z"}}]}}}