# CVE-2026-19184: Out-of-bounds write in the NXP GAU ADC driver due to byte-versus-sample buffer size validation mismatch > A buffer size validation error in the NXP GAU ADC driver allows user-mode threads to trigger out-of-bounds writes, leading to kernel memory corruption or privilege escalation. - **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** No - **Published:** 5 Oct 2026 - **Updated:** 5 Oct 2026 - **Also known as:** GHSA-j86w-mfgw-fxj9 ## What is CVE-2026-19184? CVE-2026-19184 is a high-severity memory corruption vulnerability in zephyrproject zephyr, published on 5 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim. ### Official 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. adc_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. The 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. The 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. Weakness: CWE-787 (Out-of-bounds Write) ## Which versions are affected by CVE-2026-19184? ## How do I fix CVE-2026-19184? No fix has been published for CVE-2026-19184 yet. Limit exposure of the affected software until one is available. ## Is CVE-2026-19184 being exploited? There is no known exploitation of CVE-2026-19184 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-19184 and fix it if it is affected. What it is: CVE-2026-19184 is a high-severity memory corruption vulnerability in zephyrproject zephyr, published on 5 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-19184 in the wild and no public exploit code. Affected product: zephyrproject zephyr. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-19184/ (Markdown: https://insights.sbomify.com/CVE-2026-19184/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-19184 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-19184 - OSV: https://osv.dev/vulnerability/CVE-2026-19184 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-19184/ Summaries are generated and may contain mistakes; the official description above is the record.