{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-75083", "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "state": "PUBLISHED", "assignerShortName": "zephyr", "dateReserved": "2026-08-17T16:17:45.295Z", "datePublished": "2026-10-14T16:45:56.541Z", "dateUpdated": "2026-10-16T15:31:46.531Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "shortName": "zephyr", "dateUpdated": "2026-10-14T16:45:56.541Z" }, "title": "Integer underflow of the radio-reported frame length causes an out-of-bounds write in the NXP KW41Z IEEE 802.15.4 driver", "descriptions": [ { "lang": "en", "value": "The receive path of the NXP KW41Z IEEE 802.15.4 driver, kw41z_rx() in drivers/ieee802154/ieee802154_kw41z.c, computed the payload size as pkt_len = len - KW41Z_FCS_LENGTH in a uint8_t, where len is the frame length reported by the radio. The interrupt handler kw41z_isr() obtained that length from the RX_FRAME_LENGTH field of the ZLL IRQSTS register — a copy of the PHY header length byte of the frame received over the air — and only rejected the value zero. A reported length of one therefore underflowed to pkt_len == 255.\n\nBecause the packet is allocated with NET_AF_UNSPEC on a non-Ethernet L2, net_pkt_rx_alloc_with_buffer() does not clamp the request to the interface MTU; with the default fixed-size buffer pool (CONFIG_NET_BUF_FIXED_DATA_SIZE, CONFIG_NET_BUF_DATA_SIZE=128) the allocation succeeded as a chain of two fragments. The subsequent register-to-buffer copy loops write into the first fragment only, so 255 bytes were written into a 128-byte net_buf data block, overrunning it by up to 127 bytes into adjacent network-buffer-pool memory, and reading up to 128 bytes past the end of the radio's PKT_BUFFER_RX register array.\n\nThe length field originates from an unauthenticated frame transmitted by any device within 802.15.4 radio range, and is captured by the hardware at PHY-header time — before frame filtering has completed — while the handler samples it after clearing the interrupt status, so an attacker flooding frames with a length byte of one can drive the underflow. The impact is memory corruption in the shared receive buffer pool from interrupt context, most plausibly a crash or corruption of other packets' data; the overflowing bytes are radio register contents rather than attacker-authored data, which bounds the integrity impact.\n\nThe fix rejects any length below KW41Z_FCS_LENGTH and additionally verifies net_buf_tailroom() of the first fragment before the copy loops, which also covers the CONFIG_NET_L2_OPENTHREAD variant of the size computation." } ], "affected": [ { "vendor": "zephyrproject", "product": "zephyr", "collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "packageName": "zephyr", "defaultStatus": "unaffected", "programFiles": [ "drivers/ieee802154/ieee802154_kw41z.c" ], "programRoutines": [ { "name": "kw41z_isr" }, { "name": "kw41z_rx" } ], "versions": [ { "version": "1.8.0", "status": "affected", "lessThan": "4.5.0", "versionType": "semver" } ] } ], "references": [ { "url": "https://github.com/zephyrproject-rtos/zephyr/commit/51d71864578c08eb1a1201f87b46ec81c8609d62", "name": "Fix commit", "tags": [ "patch" ] }, { "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2pwx-gg6f-535f", "name": "GHSA-2pwx-gg6f-535f" } ], "metrics": [ { "format": "CVSS", "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H", "baseScore": 5.9, "baseSeverity": "MEDIUM" } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "description": "integer-overflow", "cweId": "CWE-191", "type": "CWE" } ] } ], "x_generator": { "engine": "cvelib 1.8.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-75083", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2026-10-16T15:25:03.202886Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T15:31:46.531Z" } } ] } }