{"cve":{"cve_id":"CVE-2026-9771","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.00142,"epss_percentile":0.03152,"epss_as_of":"2026-10-15","description":"The flash_copy() system call is verified by z_vrfy_flash_copy() in drivers/flash/flash_util.c. On builds with CONFIG_USERSPACE enabled, this handler is the kernel-side trust boundary for a user-mode caller. Prior to the fix it validated only the output buffer (K_SYSCALL_MEMORY_WRITE) and passed the two struct device * arguments, src_dev and dst_dev, directly into the implementation without any object validation — unlike every sibling flash syscall, which guards its device pointer with K_SYSCALL_DRIVER_FLASH.\n\nA user-mode thread fully controls the values of src_dev/dst_dev and the contents of its own address space. The implementation z_impl_flash_copy() dereferences these pointers and calls through their driver-API function tables (e.g. api->get_parameters(dst_dev), flash_read(src_dev, ...), flash_write(dst_dev, ...)). By supplying a pointer to a forged struct device whose api table contains attacker-chosen function pointers, an unprivileged thread can cause the kernel to call arbitrary code in supervisor mode; passing any arbitrary or invalid address otherwise yields a kernel crash or out-of-bounds read.\n\nThe result is a local privilege escalation out of the userspace sandbox (with kernel denial-of-service and information disclosure as lesser outcomes). The fix adds K_SYSCALL_DRIVER_FLASH(src_dev, read) and K_SYSCALL_DRIVER_FLASH(dst_dev, write) to z_vrfy_flash_copy(), which verify each device is a registered flash-driver kernel object the calling thread is permitted to use before any dereference, closing the path completely.","published_at":"2026-08-17T16:18:52.514000Z","last_modified_at":"2026-10-23T16:10:00.313000Z","cvss_v3_score":8.8,"cvss_v3_vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","cvss_v3_severity":"HIGH","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-822","CWE-862"],"nvd_references":["https://github.com/zephyrproject-rtos/zephyr/commit/1b1ecdc438092cdd469319a0d51cba6cf82e06f4","https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-68cj-3hg4-5vpm"],"vuln_status":"Awaiting Analysis","trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-08-17T16:39:44.493675Z","updated_at":"2026-10-25T12:33:38.660090Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"L","value_label":"Local"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"L","value_label":"Low"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"C","value_label":"Changed"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"H","value_label":"High"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"zephyrproject","vendor_name":"zephyrproject","product_slug":"zephyr","product_name":"zephyr","version_start":"4.0.0","version_start_inclusive":true,"version_end":"4.4.2","version_end_inclusive":false,"cpe23_uri":"cve5:zephyrproject:zephyr:4.0.0:4.4.2"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/1b1ecdc438092cdd469319a0d51cba6cf82e06f4","source_type":"PATCH","tags":["patch"]},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-68cj-3hg4-5vpm","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2026-08-17T16:18:52.514000Z","label":"CVE published","source":null}]}