{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-12365",
        "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
        "state": "PUBLISHED",
        "assignerShortName": "zephyr",
        "dateReserved": "2026-06-16T03:53:45.082Z",
        "datePublished": "2026-08-14T17:52:05.922Z",
        "dateUpdated": "2026-08-14T19:22:24.206Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
                "shortName": "zephyr",
                "dateUpdated": "2026-08-14T17:52:05.922Z"
            },
            "title": "Use-after-free in Zephyr delayable work-queue cancellation under SMP timing race",
            "descriptions": [
                {
                    "lang": "en",
                    "value": "A use-after-free exists in the Zephyr second-generation work queue (kernel/work.c) in the handling of delayable work timeouts. When a delayable work item's timeout has been dequeued and its handler work_timeout() is in flight (blocked acquiring the work-queue spinlock), a concurrent cancellation does not wait for that handler to finish. In unschedule_locked() the pre-fix code called z_abort_timeout(), which for an already-announcing record returns -EINVAL without removing it; cancel_async_locked() then observes the work as idle, so even k_work_cancel_delayable_sync() and k_work_flush_delayable() return without blocking on the in-flight handler.\n\nBecause those are the APIs the kernel header documents as the safe way to cancel before freeing a k_work_delayable, a caller that frees the object immediately after a successful sync cancel can race the still-pending handler. work_timeout() subsequently dereferences the freed record: it reads to->dticks via z_is_timeout_handler_canceled() and, if the freed slot has been reused so the bail check fails, performs a read-modify-write of wp->flags (K_WORK_DELAYED_BIT) and submits work against a stale dw->queue pointer — a use-after-free read and write.\n\nThe k_work API is kernel-mode only (no __syscall entry point), so this is a kernel-internal concurrency defect rather than a userspace privilege escalation. Triggering it requires an SMP build and a subsystem that schedules and then frees (or reschedules) a delayable work item in the narrow window while its timeout is announcing; an attacker able to influence the timing of such teardown (for example via connection churn driving subsystem timers) has a plausible but probabilistic path. The impact is kernel memory corruption or crash (denial of service).\n\nThe fix makes unschedule_locked() wait, by spinning on z_try_abort_timeout() returning -EAGAIN while releasing and re-acquiring the work spinlock, until any in-flight handler completes before returning, and switches work_timeout() to atomic K_WORK_DELAYED_BIT ownership. This closes both the free-then-handler use-after-free and the related reschedule early-fire race."
                }
            ],
            "affected": [
                {
                    "vendor": "zephyrproject",
                    "product": "zephyr",
                    "collectionURL": "https://github.com/zephyrproject-rtos/zephyr",
                    "packageName": "zephyr",
                    "defaultStatus": "unaffected",
                    "programFiles": [
                        "kernel/work.c"
                    ],
                    "versions": [
                        {
                            "version": "2.6.0",
                            "status": "affected",
                            "lessThan": "4.5.0",
                            "versionType": "semver"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://github.com/zephyrproject-rtos/zephyr/commit/59cf34bf212eeb5c7ea88b97e15842b1e7c1a6b7",
                    "name": "Fix commit",
                    "tags": [
                        "patch"
                    ]
                },
                {
                    "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-rhmh-r93p-6g99",
                    "name": "GHSA-rhmh-r93p-6g99"
                }
            ],
            "metrics": [
                {
                    "format": "CVSS",
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H",
                        "baseScore": 5.8,
                        "baseSeverity": "MEDIUM"
                    }
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "description": "use-after-free",
                            "cweId": "CWE-416",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "x_generator": {
                "engine": "cvelib 1.8.0"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-08-14T19:22:10.432615Z",
                                "id": "CVE-2026-12365",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
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                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
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                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-08-14T19:22:24.206Z"
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}