{"schema":"threatline.record/2","record":{"id":"CVE-2026-75085","aliases":["GHSA-w7pm-4r95-c9vr"],"summary":"Out-of-bounds read from received-frame length underflow in the STM32WBA IEEE 802.15.4 driver","details":"The STM32WBA IEEE 802.15.4 driver in drivers/ieee802154/ieee802154_stm32wba.c computed the packet length of a received frame as pkt_len = rx_frame->length - IEEE802154_FCS_LENGTH without first checking that the radio-reported length could hold an FCS. pkt_len is a uint8_t, so a reported length of 0 or 1 wrapped to 254 or 255. The only bound on the resulting value was __ASSERT_NO_MSG(pkt_len <= CONFIG_NET_BUF_DATA_SIZE), which compiles to nothing in the default production configuration (CONFIG_ASSERT=n).\n\nThe length originates in the ST link-layer receive-done metadata (p_metadata->length, stored by stm32wba_802154_receive_done()), and ultimately in the PHY header of a frame received over the air, so it is influenced by any attacker within radio range of the device. Reaching the underflow requires the vendor link layer to surface a frame shorter than the FCS with no error; the driver performed no validation of its own on that value.\n\nWhen the underflow occurs, stm32wba_802154_rx_thread() calls net_pkt_write(pkt, rx_frame->psdu, pkt_len) with a length of about 254 bytes against a receive buffer that holds at most one PHY packet (IEEE802154_MAX_PHY_PACKET_SIZE, 127 bytes). This reads roughly 128 bytes past the end of the radio receive buffer and copies that adjacent memory into a network packet that is submitted to the networking stack, giving an out-of-bounds read with a potential disclosure of adjacent RAM plus needless oversized packet allocation in the RX thread.\n\nThe fix rejects a frame whose reported length is smaller than IEEE802154_FCS_LENGTH before the subtraction, and replaces the compiled-out assertion with a runtime length check that drops oversized frames — matching the runtime check already present in drivers/ieee802154/ieee802154_nrf5.c.","categories":["Unclassified"],"product":"zephyr","vendor":"zephyrproject","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-75085","source_modified_at":"2026-10-16T15:31:45.899Z","fetched_at":"2026-10-23T18:48:36.087640Z","product":"zephyr","vendor":"zephyrproject","versions":[{"version":"4.3.0","status":"affected","versionType":"semver","lessThanOrEqual":"4.4.2"}],"defaultStatus":"unaffected"}],"fixed_versions":[],"cvss":4.2,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00205,"percentile":0.10018,"score_date":"2026-10-23"},"published_at":"2026-10-14T16:46:02.993Z","modified_at":"2026-10-16T15:31:45.899Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-75085","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2026-10-16T15:31:45.899Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-75085","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/zephyrproject-rtos/zephyr/commit/46f8af4f5ee472abc13b0291c44fdfe4ed879aaa","tags":["patch"]},{"source":"CVE List","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-w7pm-4r95-c9vr"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"none","automatable":"no","technical_impact":"partial","assessed_at":"2026-10-16T15:23:46.554080Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-16T15:31:45.899Z","content_hash":"0f298cde61ad337ce08ab9a8adc4ad85a6a9fb686c1ae1ed4142293a27e0d6c8"}}