{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-9771", "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "state": "PUBLISHED", "assignerShortName": "zephyr", "dateReserved": "2026-05-27T22:08:41.676Z", "datePublished": "2026-08-17T16:18:52.514Z", "dateUpdated": "2026-08-17T16:18:52.514Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "shortName": "zephyr", "dateUpdated": "2026-08-17T16:18:52.514Z"}, "title": "Missing device-pointer validation in flash_copy() syscall allows userspace privilege escalation", "descriptions": [{"lang": "en", "value": "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 \u2014 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."}], "affected": [{"vendor": "zephyrproject", "product": "zephyr", "collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "packageName": "zephyr", "defaultStatus": "unaffected", "programFiles": ["drivers/flash/flash_util.c"], "versions": [{"version": "4.0.0", "status": "affected", "versionType": "semver", "lessThan": "4.4.2"}]}], "references": [{"url": "https://github.com/zephyrproject-rtos/zephyr/commit/1b1ecdc438092cdd469319a0d51cba6cf82e06f4", "name": "Fix commit", "tags": ["patch"]}, {"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-68cj-3hg4-5vpm", "name": "GHSA-68cj-3hg4-5vpm"}], "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH"}}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "memory-safety", "cweId": "CWE-822", "type": "CWE"}, {"lang": "en", "description": "memory-safety", "cweId": "CWE-862", "type": "CWE"}]}], "x_generator": {"engine": "cvelib 1.8.0"}}}}

{}

{"affected": [{"affectedData": [{"collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "defaultStatus": "unaffected", "packageName": "zephyr", "product": "zephyr", "programFiles": ["drivers/flash/flash_util.c"], "vendor": "zephyrproject", "versions": [{"lessThan": "4.4.2", "status": "affected", "version": "4.0.0", "versionType": "semver"}]}], "source": "vulnerabilities@zephyrproject.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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 \u2014 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."}], "id": "CVE-2026-9771", "lastModified": "2026-08-17T17:16:57.720", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.0, "impactScore": 6.0, "source": "vulnerabilities@zephyrproject.org", "type": "Secondary"}]}, "published": "2026-08-17T17:16:57.720", "references": [{"source": "vulnerabilities@zephyrproject.org", "url": "https://github.com/zephyrproject-rtos/zephyr/commit/1b1ecdc438092cdd469319a0d51cba6cf82e06f4"}, {"source": "vulnerabilities@zephyrproject.org", "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-68cj-3hg4-5vpm"}], "sourceIdentifier": "vulnerabilities@zephyrproject.org", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-822"}, {"lang": "en", "value": "CWE-862"}], "source": "vulnerabilities@zephyrproject.org", "type": "Secondary"}]}

{}

{}