{"schemaVersion":3,"id":"CVE-2026-75083","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"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.","dates":{"published":"2026-10-14T16:45:56.541Z","modified":"2026-10-16T15:31:46.531Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":5.9,"severity":"medium","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":5.9,"severity":"medium","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":5.9,"severity":"medium","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00229,"percentile":0.12873,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[{"date":"2026-10-15T00:00:00.000Z","score":0.00229,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00229,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00229,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00229,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00229,"percentile":0.12873}],"last30":[{"date":"2026-10-15T00:00:00.000Z","score":0.00229,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00229,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00229,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00229,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00229,"percentile":0.12873}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-191","name":"Integer Underflow (Wrap or Wraparound)","description":"The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/191.html"}],"affected":[{"vendor":"zephyrproject","product":"zephyr","name":"zephyr","label":"zephyr","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 1.8.0, < 4.5.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 1.8.0, < 4.5.0","eol":null,"hubHref":"/vendor/zephyrproject/zephyr"}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/51d71864578c08eb1a1201f87b46ec81c8609d62","label":"github.com/zephyrproject-rtos/zephyr/commit/51d71864578c08eb1a1201f87b46ec81c8609d62","hostname":"github.com","tags":["Patch"]},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2pwx-gg6f-535f","label":"github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2pwx-gg6f-535f","hostname":"github.com","tags":[]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-10-14T16:45:56.541Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-10-16T15:31:46.531Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":24,"level":"low","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-19T23:33:25.762Z","stale":false,"partial":false}}