{"id":"CVE-2026-19184","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-19184","generatedAt":"2026-10-28T05:59:46.438Z","title":"The written words are 16-bit ADC conversion results, so the content is only partially attacker-influenced (via the selected analog input, gain and resolution), but the destination and length are fully controlled — sufficient for kernel memory…","description":"The NXP GAU ADC driver (drivers/adc/adc_mcux_gau_adc.c) validated the caller-supplied sequence->buffer_size, which is expressed in bytes, against the number of active channels, which is a sample count. It then stored that byte count directly in data->results_length and used it in mcux_gau_adc_read_samples() as the number of uint16_t slots available. Because each conversion result occupies sizeof(uint16_t) bytes, a buffer that was accepted as \"large enough\" could be written with up to twice its size in bytes, so every sample past the buffer's midpoint was written out of bounds.\n\nadc_read() and adc_read_async() are Zephyr system calls. The syscall verifier in drivers/adc/adc_handlers.c only confirms that the caller owns buffer_size writable bytes (K_SYSCALL_MEMORY_WRITE); deciding whether that size is sufficient for the requested channels and extra_samplings is delegated entirely to the driver. On a build with CONFIG_USERSPACE=y, a user-mode thread that has been granted the ADC device object could therefore submit a deliberately half-sized buffer and cause the driver's work-queue handler — which runs in supervisor mode, outside the caller's MPU restrictions — to write ADC conversion results past the end of that buffer, at an address and for a length of the caller's choosing.\n\nThe overrun is bounded by the requested sequence: with sequence->options->extra_samplings set, the sampling loop walks the buffer pointer forward across every sampling, so the total overrun can reach the full size of the supplied buffer (kilobytes for a large extra_samplings). The written words are 16-bit ADC conversion results, so the content is only partially attacker-influenced (via the selected analog input, gain and resolution), but the destination and length are fully controlled — sufficient for kernel memory corruption, a crash, or a userspace-to-kernel privilege escalation. Builds without CONFIG_USERSPACE, or on SoCs other than NXP RW61x with the GAU ADC node enabled, are not exposed to the privilege boundary; there the same defect only causes a silent overflow when the application itself passes an undersized buffer.\n\nThe fix replaces the ad-hoc check with the shared adc_sequence_validate_buffer() helper (validating against num_channels * sizeof(uint16_t)), stores buffer_size / sizeof(uint16_t) in results_length, and corrects the loop bound to a post-decrement so exactly the available number of slots may be written.","published":"2026-10-05T09:17:13.000Z","lastModified":"2026-10-06T15:27:06.000Z","status":"Awaiting Analysis","sourceIdentifier":"vulnerabilities@zephyrproject.org","cvss":{"version":"3.1","score":8.4,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H"},"cwe":["CWE-787"],"affected":[],"epss":{"score":0.00103,"percentile":0.00956,"date":"2026-10-27","history":[{"date":"2026-10-05","score":0.00103,"percentile":0.00897}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.10%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-05T09:17:13.000Z","detail":{"score":"8.4","severity":"HIGH","publishedAt":"2026-10-05T09:17:12.907Z"},"summary":"New CVE, high severity (CVSS 8.4)."}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/82b11958065aa85f8644ddc318ff4a328d1443c8","source":"vulnerabilities@zephyrproject.org"},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-j86w-mfgw-fxj9","source":"vulnerabilities@zephyrproject.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-19184","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."}