{"id":"CVE-2026-75083","summary":"Integer underflow of the radio-reported frame length causes an out-of-bounds write in the NXP KW41Z IEEE 802.15.4 driver","details":"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.","aliases":["GHSA-2pwx-gg6f-535f"],"modified":"2026-10-17T02:48:25.545178782Z","published":"2026-10-14T16:45:56.541Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/75xxx/CVE-2026-75083.json","unresolved_ranges":[{"extracted_events":[{"introduced":"1.8.0"},{"fixed":"4.5.0"}],"source":"AFFECTED_FIELD"}],"cna_assigner":"zephyr","cwe_ids":["CWE-191"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/75xxx/CVE-2026-75083.json"},{"type":"ADVISORY","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2pwx-gg6f-535f"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-75083"},{"type":"FIX","url":"https://github.com/zephyrproject-rtos/zephyr/commit/51d71864578c08eb1a1201f87b46ec81c8609d62"},{"type":"PACKAGE","url":"https://github.com/zephyrproject-rtos/zephyr"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/zephyrproject-rtos/zephyr","events":[{"introduced":"0"},{"fixed":"51d71864578c08eb1a1201f87b46ec81c8609d62"}],"database_specific":{"source":"REFERENCES"}}],"versions":["v4.4.0","v4.4.0-rc3","v4.4.0-rc2","v4.4.0-rc1","v4.3.0","v4.3.0-rc3","v4.3.0-rc2","v4.3.0-rc1","v4.2.0","v4.2.0-rc3","v4.2.0-rc2","v4.2.0-rc1","v4.1.0","v4.1.0-rc3","v4.1.0-rc2","v4.1.0-rc1","v4.0.0","v4.0.0-rc3","v4.0.0-rc2","v4.0.0-rc1","v3.7.0","v3.7.0-rc3","v3.7.0-rc2","v3.7.0-rc1","v3.6.0","v3.6.0-rc3","v3.6.0-rc2","v3.6.0-rc1","zephyr-v3.5.0","v3.5.0","v3.5.0-rc3","v3.5.0-rc2","v3.5.0-rc1","zephyr-v3.4.0","v3.4.0","v3.4.0-rc3","v3.4.0-rc2","v3.4.0-rc1","zephyr-v3.3.0","v3.3.0","v3.3.0-rc3","v3.3.0-rc2","v3.3.0-rc1","zephyr-v3.2.0","v3.2.0","v3.2.0-rc3","v3.2.0-rc2","v3.2.0-rc1","zephyr-v3.1.0","v3.1.0","v3.1.0-rc3","v3.1.0-rc2","v3.1.0-rc1","zephyr-v3.0.0","v3.0.0","v3.0.0-rc3","v3.0.0-rc2","v3.0.0-rc1","v2.7.99","v2.7.0-rc3","v2.7.0-rc2","v2.7.0-rc1","zephyr-v2.6.0","v2.6.0","v2.6.0-rc3","v2.6.0-rc2","v2.6.0-rc1","zephyr-v2.5.0","v2.5.0","v2.5.0-rc4","v2.5.0-rc3","v2.5.0-rc2","v2.5.0-rc1","zephyr-v2.4.0","v2.4.0","v2.4.0-rc3","v2.4.0-rc2","v2.4.0-rc1","zephyr-v2.3.0","v2.3.0","v2.3.0-rc2","v2.3.0-rc1","zephyr-v2.1.0","v2.1.0","zephyr-v2.2.0","v2.2.0","v2.2.0-rc3","v2.2.0-rc2","v2.2.0-rc1","v2.1.0-rc3","v2.1.0-rc2","v2.1.0-rc1","zephyr-v2.0.0","v2.0.0","v2.0.0-rc3","v2.0.0-rc2","v2.0.0-rc1","zephyr-v1.14.0","v1.14.0","v1.14.0-rc3","v1.14.0-rc2","v1.14.0-rc1","zephyr-v1.13.0","v1.13.0","v1.13.0-rc3","v1.13.0-rc2","v1.13.0-rc1","zephyr-v1.12.0","v1.12.0","v1.12.0-rc3","v1.12.0-rc2","v1.12.0-rc1","zephyr-v1.11.0","v1.11.0","v1.11.0-rc3","v1.11.0-rc2","v1.11.0-rc1","zephyr-v1.10.0","v1.10.0","v1.10.0-rc3","v1.10.0-rc2","v1.10.0-rc1","zephyr-v1.9.0","v1.9.0","v1.9.0-rc4","v1.9.0-rc3","v1.9.0-rc2","v1.9.0-rc1","v1.8.99","zephyr-v1.5.0","v1.5.0","v1.7.99","v1.6.99","v1.5.0-rc4","v1.5.0-rc3","v1.5.0-rc2","v1.5.0-rc1","v1.5.0-rc0","zephyr-v1.4.0","v1.4.0","v1.4.0-rc3","v1.4.0-rc2","v1.4.0-rc1","zephyr-v1.3.0","v1.3.0","v1.3.0-rc2","v1.3.0-rc1","zephyr-v1.2.0","v1.2.0","v1.2.0-rc2","v1.2.0-rc1","zephyr-v1.1.0","v1.1.0","v1.1.0-rc1","zephyr-v1.0.0","v1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-75083.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H"}]}