{"id":"CVE-2026-75084","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-75084","generatedAt":"2026-10-28T07:41:01.288Z","title":"An unauthenticated attacker within radio range can transmit a frame that presents a length byte above the IEEE 802.15.4 maximum of 127 while the chip's 128-byte RX FIFO has not overflowed, so the driver's RX_FIFO_ERROR pre-check does not fire.","description":"The CC1200 sub-GHz IEEE 802.15.4 driver takes the PHY packet length from the first byte of the radio's RX FIFO in get_packet_length() and validates it in verify_rxfifo_validity() (drivers/ieee802154/ieee802154_cc1200.c). That validation only enforced a lower bound (pkt_len < 3); its second clause rejects a FIFO that holds more bytes than declared and therefore never bounds large values. Because the driver configures the radio for variable packet length with PKT_LEN = 0xFF, the length byte is an over-the-air value of 0-255 that reached net_pkt_rx_alloc_with_buffer() and the subsequent SPI burst read unclamped.\n\nAn unauthenticated attacker within radio range can transmit a frame that presents a length byte above the IEEE 802.15.4 maximum of 127 while the chip's 128-byte RX FIFO has not overflowed, so the driver's RX_FIFO_ERROR pre-check does not fire. Reaching this state depends on RF framing and timing, since the RX thread is driven off the PKT_SYNC_RXTX signal and may sample the FIFO before a packet is complete; no pairing, authentication, or user interaction is required.\n\nWith the default CONFIG_NET_BUF_FIXED_DATA_SIZE and CONFIG_NET_BUF_DATA_SIZE=128, an allocation larger than one fragment is satisfied by a chain of fragments, but read_rxfifo_content() performs a single SPI burst of pkt_len bytes into the first fragment's buf->data and then calls net_buf_add() with the same length. A length above 128 therefore writes up to 127 bytes past the end of a fragment in the contiguous rx_bufs pool and leaves a net_buf whose len exceeds its capacity. The overflowing bytes are FIFO-underflow output rather than attacker-chosen data, so the practical impact is network-buffer-pool corruption and crashes rather than a controlled write. Only builds that enable CONFIG_IEEE802154_CC1200 with an attached CC1200 radio are affected.","published":"2026-10-14T17:19:10.000Z","lastModified":"2026-10-16T16:21:02.000Z","status":"Awaiting Analysis","sourceIdentifier":"vulnerabilities@zephyrproject.org","cvss":{"version":"3.1","score":6.8,"severity":"MEDIUM","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H"},"cwe":["CWE-787"],"affected":[],"epss":{"score":0.00286,"percentile":0.20974,"date":"2026-10-27","history":[{"date":"2026-10-15","score":0.00286,"percentile":0.19683}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.29%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-14T17:19:10.000Z","detail":{"score":"6.8","severity":"MEDIUM","publishedAt":"2026-10-14T17:19:10.457Z"},"summary":"New CVE, medium severity (CVSS 6.8)."}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/26a8b8294bf28523c7aa2f15cf728517980ee593","source":"vulnerabilities@zephyrproject.org"},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-pgg5-wwxw-vmj8","source":"vulnerabilities@zephyrproject.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-75084","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}