{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-63870", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.017Z", "datePublished": "2026-07-19T14:18:39.113Z", "dateUpdated": "2026-08-05T12:36:45.663Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:36:45.663Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nieee802154: 6lowpan: only accept IPv6 packets in lowpan_xmit()\n\nThe aoe driver (or similar) generates a non-IPv6 packet\n(e.g., ETH_P_AOE) and queues it for transmission via dev_queue_xmit()\non a 6LoWPAN interface (configured by the user or test case).\n\nSince the packet is not IPv6, the 6LoWPAN header_ops->create function\n(lowpan_header_create or header_create) returns early without initializing\nthe lowpan_addr_info structure in the skb headroom.\n\nIn the transmit function (lowpan_xmit), the driver calls lowpan_header\n(or setup_header) which unconditionally copies and uses the lowpan_addr_info\nfrom the headroom, which contains uninitialized data.\n\nFix this by dropping non IPv6 packets.\n\nA similar fix is needed in net/bluetooth/6lowpan.c bt_xmit()." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The flaw is in the transmit path (`lowpan_xmit`) reached only when locally queued skbs are sent via `dev_queue_xmit()` (syzbot: AoE → `aoenet.c:tx` → `lowpan_xmit`), not from remote 802.15.4 packet reception.\nAC:L - An attacker who can create a 6LoWPAN interface and queue non-IPv6 packets (or misconfigure AoE onto it) reliably triggers the uninitialized read; syzbot reproduced it deterministically with no race or rare layout dependency.\nPR:L - Exploitation requires creating a `lowpan` RTNL link (`CAP_NET_ADMIN`, obtainable in a user namespace) and transmitting non-IPv6 frames via `AF_PACKET` or a misbound driver; no real-root-only capability is strictly required on typical userns-enabled systems.\nUI:N - No victim interaction is needed beyond the attacker (or fuzzer) configuring the interface and injecting the malformed transmit; exploitation is fully attacker-driven.\nS:U - Impact is confined to kernel memory handling and 802.15.4 transmission on the same host; it does not cross a VM, container, or IOMMU security boundary.\nC:H - `lowpan_header()` copies uninitialized slab contents from skb headroom (`KMSAN: uninit-value` at `tx.c:231/240`) and uses them in 802.15.4 address fields, leaking kernel heap bytes that may be encoded into transmitted WPAN frames.\nI:H - Uninitialized `ieee802154_addr` values drive `wpan_dev_hard_header()` and frame transmission, allowing heap-spray-influenced 802.15.4 destinations and corrupted over-the-air frames rather than only a benign drop.\nA:H - Successful transmission of malformed WPAN frames with attacker-influenced addressing can disrupt 802.15.4 mesh/IoT availability, and memory-safety bugs on the xmit path can escalate to kernel faults under heap-controlled conditions." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ieee802154/6lowpan/tx.c" ], "versions": [ { "version": "4dc315e267fe4a3c863fec21f26aa0a418c3f07a", "lessThan": "af07fffbd53ddc3ec3c2a4ca914f27899fa89bca", "status": "affected", "versionType": "git" }, { "version": "4dc315e267fe4a3c863fec21f26aa0a418c3f07a", "lessThan": "3150e6d3223dfc356308125cabf9c34169842d2a", "status": "affected", "versionType": "git" }, { "version": "4dc315e267fe4a3c863fec21f26aa0a418c3f07a", "lessThan": "8da95cb6ad7d656c871e776a9c7b77e894d6d89c", "status": "affected", "versionType": "git" }, { "version": "4dc315e267fe4a3c863fec21f26aa0a418c3f07a", "lessThan": "1a827b95e62b4cbe851ae7cc9c961cdfa769cca4", "status": "affected", "versionType": "git" }, { "version": "4dc315e267fe4a3c863fec21f26aa0a418c3f07a", "lessThan": "c1819c8defa235c7beda859bc185b1c429a55ecd", "status": "affected", "versionType": "git" }, { "version": "4dc315e267fe4a3c863fec21f26aa0a418c3f07a", "lessThan": "285b0842f2e01c3edf805f1fd64da11d9b7f6b4c", "status": "affected", "versionType": "git" }, { "version": "4dc315e267fe4a3c863fec21f26aa0a418c3f07a", "lessThan": "87172cc8dc49aaf54407a31edffb0232f8cb93ab", "status": "affected", "versionType": "git" }, { "version": "4dc315e267fe4a3c863fec21f26aa0a418c3f07a", "lessThan": "3a5f3f7aff18bcc36a57839cf50cf0cc8de707f3", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ieee802154/6lowpan/tx.c" ], "versions": [ { "version": "4.0", "status": "affected" }, { "version": "0", "lessThan": "4.0", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.259", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.210", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.176", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.143", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.94", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.36", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.13", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndExcluding": "5.10.259" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndExcluding": "5.15.210" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndExcluding": "6.1.176" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndExcluding": "6.6.143" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndExcluding": "6.12.94" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndExcluding": "6.18.36" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndExcluding": "7.0.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/af07fffbd53ddc3ec3c2a4ca914f27899fa89bca" }, { "url": "https://git.kernel.org/stable/c/3150e6d3223dfc356308125cabf9c34169842d2a" }, { "url": "https://git.kernel.org/stable/c/8da95cb6ad7d656c871e776a9c7b77e894d6d89c" }, { "url": "https://git.kernel.org/stable/c/1a827b95e62b4cbe851ae7cc9c961cdfa769cca4" }, { "url": "https://git.kernel.org/stable/c/c1819c8defa235c7beda859bc185b1c429a55ecd" }, { "url": "https://git.kernel.org/stable/c/285b0842f2e01c3edf805f1fd64da11d9b7f6b4c" }, { "url": "https://git.kernel.org/stable/c/87172cc8dc49aaf54407a31edffb0232f8cb93ab" }, { "url": "https://git.kernel.org/stable/c/3a5f3f7aff18bcc36a57839cf50cf0cc8de707f3" } ], "title": "ieee802154: 6lowpan: only accept IPv6 packets in lowpan_xmit()", "x_generator": { "engine": "bippy-1.2.0" } } } }