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vuln-cve/data/2026/16xxx/CVE-2026-16513.json
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{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-16513",
"assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
"state": "PUBLISHED",
"assignerShortName": "zephyr",
"dateReserved": "2026-07-21T21:42:58.503Z",
"datePublished": "2026-09-28T19:59:57.736Z",
"dateUpdated": "2026-11-04T05:00:24.005Z"
},
"containers": {
"cna": {
"providerMetadata": {
"orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
"shortName": "zephyr",
"dateUpdated": "2026-11-04T05:00:24.005Z"
},
"title": "Missing write validation of user-supplied handle pointer in the RTIO syscall verifier allows arbitrary kernel write",
"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."
}
],
"affected": [
{
"vendor": "zephyrproject",
"product": "zephyr",
"collectionURL": "https://github.com/zephyrproject-rtos/zephyr",
"packageName": "zephyr",
"defaultStatus": "unaffected",
"programFiles": [
"subsys/rtio/rtio_syscalls.c"
],
"programRoutines": [
{
"name": "rtio_sqe_copy_in_get_handles"
},
{
"name": "z_vrfy_rtio_sqe_copy_in_get_handles"
}
],
"versions": [
{
"version": "3.4.0",
"status": "affected",
"versionType": "semver",
"lessThan": "4.3.2"
},
{
"version": "4.4.0",
"status": "affected",
"versionType": "semver",
"lessThan": "4.4.2"
}
]
}
],
"references": [
{
"url": "https://github.com/zephyrproject-rtos/zephyr/commit/95c355c425763fbe5e735b9ef54dacce2c4ce21f",
"name": "Fix commit",
"tags": [
"patch"
]
},
{
"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fwmc-q8qg-jcxq",
"name": "GHSA-fwmc-q8qg-jcxq"
}
],
"metrics": [
{
"format": "CVSS",
"cvssV3_1": {
"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"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"lang": "en",
"description": "memory-safety",
"cweId": "CWE-787",
"type": "CWE"
}
]
}
],
"x_generator": {
"engine": "cvelib 1.8.0"
}
},
"adp": [
{
"metrics": [
{
"other": {
"type": "ssvc",
"content": {
"id": "CVE-2026-16513",
"role": "CISA Coordinator",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-09-30T19:45:44.911882Z"
}
}
}
],
"title": "CISA ADP Vulnrichment",
"providerMetadata": {
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP",
"dateUpdated": "2026-09-30T20:11:11.980Z"
}
}
]
}
}