{"id":"CVE-2026-75085","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-75085","generatedAt":"2026-10-28T02:21:58.048Z","title":"The 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…","description":"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.","published":"2026-10-14T17:19:11.000Z","lastModified":"2026-10-16T16:21:02.000Z","status":"Awaiting Analysis","sourceIdentifier":"vulnerabilities@zephyrproject.org","cvss":{"version":"3.1","score":4.2,"severity":"MEDIUM","vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L"},"cwe":["CWE-125"],"affected":[],"epss":{"score":0.00205,"percentile":0.10435,"date":"2026-10-26","history":[{"date":"2026-10-15","score":0.00205,"percentile":0.09848}]},"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 (0.21%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-14T17:19:11.000Z","detail":{"score":"4.2","severity":"MEDIUM","publishedAt":"2026-10-14T17:19:10.607Z"},"summary":"New CVE, medium severity (CVSS 4.2)."}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/46f8af4f5ee472abc13b0291c44fdfe4ed879aaa","source":"vulnerabilities@zephyrproject.org"},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-w7pm-4r95-c9vr","source":"vulnerabilities@zephyrproject.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-75085","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."}