{"api_version":"1","generated_at":"2026-08-08T05:04:41+00:00","cve":"CVE-2026-11742","urls":{"html":"https://cve.report/CVE-2026-11742","api":"https://cve.report/api/cve/CVE-2026-11742.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-11742","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-11742"},"summary":{"title":"Use-after-free race in kernel `k_queue_peek_head/tail` due to missing spinlock","description":"The kernel queue helper z_queue_node_peek() in kernel/queue.c dereferences a node taken from a queue's data_q list, reading the node's flag byte and, for items enqueued via k_queue_alloc_append/alloc_prepend, the data pointer of an internally allocated alloc_node struct. The implementations of z_impl_k_queue_peek_head() and z_impl_k_queue_peek_tail() performed this read-and-dereference without holding the queue's spinlock, while every other accessor of the same list — including k_queue_get(), which unlinks a node and k_free()s its backing alloc_node — operates under that lock.\n\nBecause peek was unsynchronized, a concurrent k_queue_get() on the same queue (on an SMP build, or under preemption/ISR concurrency) can free the node between the moment peek obtains the node pointer and the moment it dereferences it. The peek then reads flag bits and a data pointer out of freed, potentially re-allocated heap memory and returns a stale or dangling pointer to its caller. k_fifo and k_lifo are thin wrappers over k_queue, so this affects buffer queues used throughout the net_buf, Bluetooth, USB, and networking subsystems; the peek operations are also system calls reachable from CONFIG_USERSPACE threads.\n\nThe consequences are a use-after-free read that can leak stale heap contents (one pointer word) and, when the returned dangling pointer is subsequently consumed as a live buffer, a dereference that can crash the system or corrupt memory. Exploitation requires winning a small race window with local access (e.g. a userspace process racing k_queue_peek_* against k_queue_get on a shared queue, or two CPUs), so practical impact is bounded and of low severity.\n\nThe fix wraps both peek implementations with k_spin_lock/k_spin_unlock on the queue lock, making the read-and-dereference atomic with respect to the concurrent unlink-and-free and bringing peek into line with the rest of the queue's locking discipline.","state":"PUBLISHED","assigner":"zephyr","published_at":"2026-08-07 22:16:57","updated_at":"2026-08-07 22:16:57"},"problem_types":["CWE-416","CWE-416 use-after-free"],"metrics":[{"version":"3.1","source":"vulnerabilities@zephyrproject.org","type":"Secondary","score":"3.6","severity":"LOW","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:L","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:L","baseScore":3.6,"baseSeverity":"LOW","attackVector":"LOCAL","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"LOW"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"3.6","severity":"LOW","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:L","data":{"baseScore":3.6,"baseSeverity":"LOW","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:L","version":"3.1"}}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/a6b6149a50cb0f64061869f7536acbf80ccc5e0c","name":"https://github.com/zephyrproject-rtos/zephyr/commit/a6b6149a50cb0f64061869f7536acbf80ccc5e0c","refsource":"vulnerabilities@zephyrproject.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-8xm3-4w69-29mm","name":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-8xm3-4w69-29mm","refsource":"vulnerabilities@zephyrproject.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-11742","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-11742","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"zephyrproject","product":"zephyr","version":"affected 1.12.0 4.4.2 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"collectionURL":"https://github.com/zephyrproject-rtos/zephyr","defaultStatus":"unaffected","packageName":"zephyr","product":"zephyr","programFiles":["kernel/queue.c"],"vendor":"zephyrproject","versions":[{"lessThan":"4.4.2","status":"affected","version":"1.12.0","versionType":"semver"}]}],"descriptions":[{"lang":"en","value":"The kernel queue helper z_queue_node_peek() in kernel/queue.c dereferences a node taken from a queue's data_q list, reading the node's flag byte and, for items enqueued via k_queue_alloc_append/alloc_prepend, the data pointer of an internally allocated alloc_node struct. The implementations of z_impl_k_queue_peek_head() and z_impl_k_queue_peek_tail() performed this read-and-dereference without holding the queue's spinlock, while every other accessor of the same list — including k_queue_get(), which unlinks a node and k_free()s its backing alloc_node — operates under that lock.\n\nBecause peek was unsynchronized, a concurrent k_queue_get() on the same queue (on an SMP build, or under preemption/ISR concurrency) can free the node between the moment peek obtains the node pointer and the moment it dereferences it. The peek then reads flag bits and a data pointer out of freed, potentially re-allocated heap memory and returns a stale or dangling pointer to its caller. k_fifo and k_lifo are thin wrappers over k_queue, so this affects buffer queues used throughout the net_buf, Bluetooth, USB, and networking subsystems; the peek operations are also system calls reachable from CONFIG_USERSPACE threads.\n\nThe consequences are a use-after-free read that can leak stale heap contents (one pointer word) and, when the returned dangling pointer is subsequently consumed as a live buffer, a dereference that can crash the system or corrupt memory. Exploitation requires winning a small race window with local access (e.g. a userspace process racing k_queue_peek_* against k_queue_get on a shared queue, or two CPUs), so practical impact is bounded and of low severity.\n\nThe fix wraps both peek implementations with k_spin_lock/k_spin_unlock on the queue lock, making the read-and-dereference atomic with respect to the concurrent unlink-and-free and bringing peek into line with the rest of the queue's locking discipline."}],"metrics":[{"cvssV3_1":{"baseScore":3.6,"baseSeverity":"LOW","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:L","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","description":"use-after-free","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-07T21:10:23.002Z","orgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","shortName":"zephyr"},"references":[{"name":"Fix commit","tags":["patch"],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/a6b6149a50cb0f64061869f7536acbf80ccc5e0c"},{"name":"GHSA-8xm3-4w69-29mm","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-8xm3-4w69-29mm"}],"title":"Use-after-free race in kernel `k_queue_peek_head/tail` due to missing spinlock","x_generator":{"engine":"cvelib 1.8.0"}}},"cveMetadata":{"assignerOrgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","assignerShortName":"zephyr","cveId":"CVE-2026-11742","datePublished":"2026-08-07T21:10:23.002Z","dateReserved":"2026-06-09T05:26:13.901Z","dateUpdated":"2026-08-07T21:10:23.002Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-07 22:16:57","lastModifiedDate":"2026-08-07 22:16:57","problem_types":["CWE-416","CWE-416 use-after-free"],"metrics":{"cvssMetricV31":[{"source":"vulnerabilities@zephyrproject.org","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:L","baseScore":3.6,"baseSeverity":"LOW","attackVector":"LOCAL","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"LOW"},"exploitabilityScore":1,"impactScore":2.5}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"11742","Ordinal":"1","Title":"Use-after-free race in kernel `k_queue_peek_head/tail` due to mi","CVE":"CVE-2026-11742","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"11742","Ordinal":"1","NoteData":"The kernel queue helper z_queue_node_peek() in kernel/queue.c dereferences a node taken from a queue's data_q list, reading the node's flag byte and, for items enqueued via k_queue_alloc_append/alloc_prepend, the data pointer of an internally allocated alloc_node struct. The implementations of z_impl_k_queue_peek_head() and z_impl_k_queue_peek_tail() performed this read-and-dereference without holding the queue's spinlock, while every other accessor of the same list — including k_queue_get(), which unlinks a node and k_free()s its backing alloc_node — operates under that lock.\n\nBecause peek was unsynchronized, a concurrent k_queue_get() on the same queue (on an SMP build, or under preemption/ISR concurrency) can free the node between the moment peek obtains the node pointer and the moment it dereferences it. The peek then reads flag bits and a data pointer out of freed, potentially re-allocated heap memory and returns a stale or dangling pointer to its caller. k_fifo and k_lifo are thin wrappers over k_queue, so this affects buffer queues used throughout the net_buf, Bluetooth, USB, and networking subsystems; the peek operations are also system calls reachable from CONFIG_USERSPACE threads.\n\nThe consequences are a use-after-free read that can leak stale heap contents (one pointer word) and, when the returned dangling pointer is subsequently consumed as a live buffer, a dereference that can crash the system or corrupt memory. Exploitation requires winning a small race window with local access (e.g. a userspace process racing k_queue_peek_* against k_queue_get on a shared queue, or two CPUs), so practical impact is bounded and of low severity.\n\nThe fix wraps both peek implementations with k_spin_lock/k_spin_unlock on the queue lock, making the read-and-dereference atomic with respect to the concurrent unlink-and-free and bringing peek into line with the rest of the queue's locking discipline.","Type":"Description","Title":"Use-after-free race in kernel `k_queue_peek_head/tail` due to mi"}]}}}