{"affected":[{"defaultStatus":"unaffected","ecosystem":"https://github.com/zephyrproject-rtos/zephyr","packageName":"zephyr","product":"zephyr","source":"CNA: zephyr","vendor":"zephyrproject","versions":[{"lessThan":"4.3.2","status":"affected","version":"1.12.0","versionType":"semver"},{"lessThan":"4.4.2","status":"affected","version":"4.4.0","versionType":"semver"}]}],"cveId":"CVE-2026-11742","cwes":["CWE-416"],"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.","epss":{"date":"2026-11-03","percentile":0.02413,"score":0.00127},"exploits":[],"kev":null,"metrics":[{"score":3.6,"severity":"low","source":"CNA: zephyr","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:L","version":"3.1"},{"score":3.6,"severity":"low","source":"NVD: vulnerabilities@zephyrproject.org","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:L","version":"3.1"}],"modifiedAt":1793769509600,"publishedAt":1786137023002,"references":[{"source":"CNA: zephyr","tags":["patch"],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/a6b6149a50cb0f64061869f7536acbf80ccc5e0c"},{"source":"CNA: zephyr","tags":[],"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-8xm3-4w69-29mm"},{"source":"vulnerabilities@zephyrproject.org","tags":[],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/a6b6149a50cb0f64061869f7536acbf80ccc5e0c"},{"source":"vulnerabilities@zephyrproject.org","tags":[],"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-8xm3-4w69-29mm"}],"remediation":[{"kind":"fix","source":"CNA: zephyr","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/zephyrproject-rtos/zephyr/commit/a6b6149a50cb0f64061869f7536acbf80ccc5e0c"}],"revision":"84854be764b52892ff7934e27fb3c0d2c06e1eea7afff6490130777d5623053b","sources":[{"modifiedAt":1793768350924,"name":"CNA: zephyr","retrievedAt":1793768963204,"url":"https://www.cve.org/CVERecord?id=CVE-2026-11742"},{"modifiedAt":1793769509600,"name":"NVD","retrievedAt":1793772952595,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-11742"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793768988773,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-11742"}],"ssvc":{"assessedAt":1786381032229,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"Use-after-free race in kernel `k_queue_peek_head/tail` due to missing spinlock","updatedAt":1793772952595}