{"affected":[{"defaultStatus":"unaffected","ecosystem":"https://github.com/zephyrproject-rtos/zephyr","packageName":"zephyr","product":"zephyr","source":"CNA: zephyr","vendor":"zephyrproject","versions":[{"lessThan":"4.3.2","status":"affected","version":"3.7.0","versionType":"semver"},{"lessThan":"4.5.0","status":"affected","version":"4.4.0","versionType":"semver"}]}],"cveId":"CVE-2026-19184","cwes":["CWE-787"],"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.","epss":{"date":"2026-11-03","percentile":0.00959,"score":0.00103},"exploits":[],"kev":null,"metrics":[{"score":8.4,"severity":"high","source":"CNA: zephyr","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H","version":"3.1"},{"score":8.4,"severity":"high","source":"NVD: vulnerabilities@zephyrproject.org","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H","version":"3.1"}],"modifiedAt":1793769527413,"publishedAt":1791187582681,"references":[{"source":"CNA: zephyr","tags":["patch"],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/82b11958065aa85f8644ddc318ff4a328d1443c8"},{"source":"CNA: zephyr","tags":[],"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-j86w-mfgw-fxj9"},{"source":"vulnerabilities@zephyrproject.org","tags":[],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/82b11958065aa85f8644ddc318ff4a328d1443c8"},{"source":"vulnerabilities@zephyrproject.org","tags":[],"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-j86w-mfgw-fxj9"}],"remediation":[{"kind":"fix","source":"CNA: zephyr","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/zephyrproject-rtos/zephyr/commit/82b11958065aa85f8644ddc318ff4a328d1443c8"}],"revision":"d21bf1fadb2ceff80b40e8323d3567ea9e29e57953be20d3f24b68ae38e4b315","sources":[{"modifiedAt":1793768435394,"name":"CNA: zephyr","retrievedAt":1793769075122,"url":"https://www.cve.org/CVERecord?id=CVE-2026-19184"},{"modifiedAt":1793769527413,"name":"NVD","retrievedAt":1793772969304,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-19184"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793769079585,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-19184"}],"ssvc":{"assessedAt":1791206602615,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"Out-of-bounds write in the NXP GAU ADC driver due to byte-versus-sample buffer size validation mismatch","updatedAt":1793772969304}