{"api_version":"1","generated_at":"2026-10-30T20:45:41+00:00","cve":"CVE-2026-16513","urls":{"html":"https://cve.report/CVE-2026-16513","api":"https://cve.report/api/cve/CVE-2026-16513.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-16513","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-16513"},"summary":{"title":"Missing write validation of user-supplied handle pointer in the RTIO syscall verifier allows arbitrary kernel write","description":"The userspace verifier z_vrfy_rtio_sqe_copy_in_get_handles() in subsys/rtio/rtio_syscalls.c (subsys/rtio/rtio_handlers.c before v4.3.0) validated the RTIO object handle and the sqes input array, but not the handle out-parameter. On the first loop iteration it executed *handle = sqe, storing the kernel address of the newly acquired submission-queue entry through a pointer taken verbatim from user mode, with no K_SYSCALL_MEMORY_WRITE check in front of it.\n\nAny user-mode thread that has been granted a struct rtio kernel object can invoke the syscall with an arbitrary address in handle. That is the ordinary way an unprivileged thread uses the RTIO API, for example via sensor_read_async_mempool() or the async ADC helpers, which call rtio_sqe_copy_in_get_handles() internally. The store happens in supervisor mode before any submission-entry validation, so it fires regardless of whether the SQE contents are subsequently rejected. Only builds with CONFIG_USERSPACE and CONFIG_RTIO are affected; without CONFIG_USERSPACE the verifier is not compiled and the caller is already privileged.\n\nThe write address is fully attacker-chosen and the written value is a pointer into the caller's own RTIO ring, whose contents the caller controls (the following *sqe = sqes[i] copies an attacker-supplied struct rtio_sqe into that slot). This yields a write-what-where primitive placing a pointer to attacker-controlled data at any kernel address, sufficient to corrupt kernel function pointers, thread structures, or memory-domain partition tables, and thus to escalate from user mode to kernel mode, defeating the isolation boundary CONFIG_USERSPACE is meant to enforce. At minimum it is a reliable kernel memory-corruption and crash primitive. The reporter reproduced the write on qemu_x86: a K_USER thread changed a supervisor global from NULL to a live kernel SQE pointer.\n\nThe fix adds K_SYSCALL_MEMORY_WRITE(handle, sizeof(*handle)) (guarded by the existing optional-NULL semantics) before the loop, so the destination must lie in the calling thread's writable memory domain or the thread is terminated by K_OOPS. The neighbouring verifier z_vrfy_rtio_cqe_get_mempool_buffer(), which checked its buff/buff_len out-parameters only for read although the implementation writes through them, was hardened separately by bea93400138 (\"rtio: syscalls: validate output params as writable\"); that residual was materially weaker, since a read check still confines the target to the caller's own memory domain.","state":"PUBLISHED","assigner":"zephyr","published_at":"2026-09-28 21:17:16","updated_at":"2026-10-27 15:21:44"},"problem_types":["CWE-787","CWE-787 memory-safety"],"metrics":[{"version":"3.1","source":"vulnerabilities@zephyrproject.org","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/95c355c425763fbe5e735b9ef54dacce2c4ce21f","name":"https://github.com/zephyrproject-rtos/zephyr/commit/95c355c425763fbe5e735b9ef54dacce2c4ce21f","refsource":"vulnerabilities@zephyrproject.org","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fwmc-q8qg-jcxq","name":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fwmc-q8qg-jcxq","refsource":"vulnerabilities@zephyrproject.org","tags":["Exploit","Patch","Vendor Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-16513","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-16513","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"zephyrproject","product":"zephyr","version":"affected 3.4.0 4.4.2 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2026","cve_id":"16513","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"zephyrproject","cpe5":"zephyr","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"16513","cve":"CVE-2026-16513","epss":"0.001120000","percentile":"0.013600000","score_date":"2026-10-27","updated_at":"2026-10-28 00:14:12"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-16513","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","timestamp":"2026-09-30T19:45:44.911882Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-09-30T20:11:11.980Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"collectionURL":"https://github.com/zephyrproject-rtos/zephyr","defaultStatus":"unaffected","packageName":"zephyr","product":"zephyr","programFiles":["subsys/rtio/rtio_syscalls.c"],"programRoutines":[{"name":"rtio_sqe_copy_in_get_handles"},{"name":"z_vrfy_rtio_sqe_copy_in_get_handles"}],"vendor":"zephyrproject","versions":[{"lessThan":"4.4.2","status":"affected","version":"3.4.0","versionType":"semver"}]}],"descriptions":[{"lang":"en","value":"The userspace verifier z_vrfy_rtio_sqe_copy_in_get_handles() in subsys/rtio/rtio_syscalls.c (subsys/rtio/rtio_handlers.c before v4.3.0) validated the RTIO object handle and the sqes input array, but not the handle out-parameter. On the first loop iteration it executed *handle = sqe, storing the kernel address of the newly acquired submission-queue entry through a pointer taken verbatim from user mode, with no K_SYSCALL_MEMORY_WRITE check in front of it.\n\nAny user-mode thread that has been granted a struct rtio kernel object can invoke the syscall with an arbitrary address in handle. That is the ordinary way an unprivileged thread uses the RTIO API, for example via sensor_read_async_mempool() or the async ADC helpers, which call rtio_sqe_copy_in_get_handles() internally. The store happens in supervisor mode before any submission-entry validation, so it fires regardless of whether the SQE contents are subsequently rejected. Only builds with CONFIG_USERSPACE and CONFIG_RTIO are affected; without CONFIG_USERSPACE the verifier is not compiled and the caller is already privileged.\n\nThe write address is fully attacker-chosen and the written value is a pointer into the caller's own RTIO ring, whose contents the caller controls (the following *sqe = sqes[i] copies an attacker-supplied struct rtio_sqe into that slot). This yields a write-what-where primitive placing a pointer to attacker-controlled data at any kernel address, sufficient to corrupt kernel function pointers, thread structures, or memory-domain partition tables, and thus to escalate from user mode to kernel mode, defeating the isolation boundary CONFIG_USERSPACE is meant to enforce. At minimum it is a reliable kernel memory-corruption and crash primitive. The reporter reproduced the write on qemu_x86: a K_USER thread changed a supervisor global from NULL to a live kernel SQE pointer.\n\nThe fix adds K_SYSCALL_MEMORY_WRITE(handle, sizeof(*handle)) (guarded by the existing optional-NULL semantics) before the loop, so the destination must lie in the calling thread's writable memory domain or the thread is terminated by K_OOPS. The neighbouring verifier z_vrfy_rtio_cqe_get_mempool_buffer(), which checked its buff/buff_len out-parameters only for read although the implementation writes through them, was hardened separately by bea93400138 (\"rtio: syscalls: validate output params as writable\"); that residual was materially weaker, since a read check still confines the target to the caller's own memory domain."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-787","description":"memory-safety","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-09-28T19:59:57.736Z","orgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","shortName":"zephyr"},"references":[{"name":"Fix commit","tags":["patch"],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/95c355c425763fbe5e735b9ef54dacce2c4ce21f"},{"name":"GHSA-fwmc-q8qg-jcxq","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fwmc-q8qg-jcxq"}],"title":"Missing write validation of user-supplied handle pointer in the RTIO syscall verifier allows arbitrary kernel write","x_generator":{"engine":"cvelib 1.8.0"}}},"cveMetadata":{"assignerOrgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","assignerShortName":"zephyr","cveId":"CVE-2026-16513","datePublished":"2026-09-28T19:59:57.736Z","dateReserved":"2026-07-21T21:42:58.503Z","dateUpdated":"2026-09-30T20:11:11.980Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-28 21:17:16","lastModifiedDate":"2026-10-27 15:21:44","problem_types":["CWE-787","CWE-787 memory-safety"],"metrics":{"cvssMetricV31":[{"source":"vulnerabilities@zephyrproject.org","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-30T19:45:44.911882Z","id":"CVE-2026-16513","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:zephyrproject:zephyr:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4.0","versionEndExcluding":"4.4.2","matchCriteriaId":"325B1699-5FEF-4381-89B1-58836AB33A3A"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"16513","Ordinal":"1","Title":"Missing write validation of user-supplied handle pointer in the ","CVE":"CVE-2026-16513","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"16513","Ordinal":"1","NoteData":"The userspace verifier z_vrfy_rtio_sqe_copy_in_get_handles() in subsys/rtio/rtio_syscalls.c (subsys/rtio/rtio_handlers.c before v4.3.0) validated the RTIO object handle and the sqes input array, but not the handle out-parameter. On the first loop iteration it executed *handle = sqe, storing the kernel address of the newly acquired submission-queue entry through a pointer taken verbatim from user mode, with no K_SYSCALL_MEMORY_WRITE check in front of it.\n\nAny user-mode thread that has been granted a struct rtio kernel object can invoke the syscall with an arbitrary address in handle. That is the ordinary way an unprivileged thread uses the RTIO API, for example via sensor_read_async_mempool() or the async ADC helpers, which call rtio_sqe_copy_in_get_handles() internally. The store happens in supervisor mode before any submission-entry validation, so it fires regardless of whether the SQE contents are subsequently rejected. Only builds with CONFIG_USERSPACE and CONFIG_RTIO are affected; without CONFIG_USERSPACE the verifier is not compiled and the caller is already privileged.\n\nThe write address is fully attacker-chosen and the written value is a pointer into the caller's own RTIO ring, whose contents the caller controls (the following *sqe = sqes[i] copies an attacker-supplied struct rtio_sqe into that slot). This yields a write-what-where primitive placing a pointer to attacker-controlled data at any kernel address, sufficient to corrupt kernel function pointers, thread structures, or memory-domain partition tables, and thus to escalate from user mode to kernel mode, defeating the isolation boundary CONFIG_USERSPACE is meant to enforce. At minimum it is a reliable kernel memory-corruption and crash primitive. The reporter reproduced the write on qemu_x86: a K_USER thread changed a supervisor global from NULL to a live kernel SQE pointer.\n\nThe fix adds K_SYSCALL_MEMORY_WRITE(handle, sizeof(*handle)) (guarded by the existing optional-NULL semantics) before the loop, so the destination must lie in the calling thread's writable memory domain or the thread is terminated by K_OOPS. The neighbouring verifier z_vrfy_rtio_cqe_get_mempool_buffer(), which checked its buff/buff_len out-parameters only for read although the implementation writes through them, was hardened separately by bea93400138 (\"rtio: syscalls: validate output params as writable\"); that residual was materially weaker, since a read check still confines the target to the caller's own memory domain.","Type":"Description","Title":"Missing write validation of user-supplied handle pointer in the "}]}}}