{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-19937 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-19937 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-19937 is a medium-severity denial of service vulnerability in zephyrproject zephyr, published on 12 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-19937 and fix it if it is affected.\n\nWhat it is: CVE-2026-19937 is a medium-severity denial of service vulnerability in zephyrproject zephyr, published on 12 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-19937 in the wild and no public exploit code.\n\nAffected product: zephyrproject zephyr. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-19937/ (Markdown: https://insights.sbomify.com/CVE-2026-19937/index.md)","id":"CVE-2026-19937","markdown":"https://insights.sbomify.com/CVE-2026-19937/index.md","name":"CVE-2026-19937","record":{"aliases":["GHSA-5rrx-xww6-5xrh"],"analysis":{"component_type":"operating_system","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Zephyr RTOS","requires_auth":"low_privilege","summary":"A remote attacker can permanently leak message contexts in Zephyr's Bluetooth Mesh, causing a denial of service by disabling all model responses.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"zephyr","cpe":[],"cvss":{"score":5.7,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-772","name":"Missing Release of Resource after Effective Lifetime"}],"description":"The Bluetooth Mesh Access layer delayable-message machinery in subsys/bluetooth/mesh/delayable_msg.c manages a static pool of CONFIG_BT_MESH_ACCESS_DELAYABLE_MSG_COUNT message contexts (default 4) threaded onto a free_ctx or busy_ctx list. release_delayable_msg_ctx() returned a context to free_ctx only when sys_slist_find_and_remove() found it on busy_ctx. The chunk-exhaustion error path in bt_mesh_delayable_msg_manage() releases a context that was already popped off free_ctx but not yet inserted on busy_ctx, so the context was appended to neither list and was permanently lost from the pool. Because bt_mesh_delayable_msg_init() runs only once from bt_mesh_init(), and node reset/suspend only drain busy_ctx, the loss survives unprovision, re-provision and suspend/resume — it is cleared only by a reboot.\n\nThe error path is reached when the chunk pool (CONFIG_BT_MESH_ACCESS_DELAYABLE_MSG_CHUNK_COUNT, default 40 chunks) is short of the chunks a new delayed message needs and the oldest pending message cannot be flushed because bt_mesh_access_send() returns -EBUSY or -ENOBUFS (all segmented-TX contexts busy, or advertising/segment buffers exhausted). A peer that is provisioned into the mesh network — holding a valid NetKey plus an AppKey or DevKey bound to a server model — can drive both conditions by flooding the victim with requests that elicit segmented responses while withholding the Segment Acknowledgment, which keeps the transmit contexts occupied while queued responses hold the chunk pool. Each further request that arrives in that window leaks one context.\n\nOnce the pool is drained, bt_mesh_delayable_msg_manage() returns -ENOMEM for every subsequent send and bt_mesh_model_send() propagates that error with no fallback to an immediate transmit. Since CONFIG_BT_MESH_ACCESS_DELAYABLE_MSG and CONFIG_BT_MESH_ACCESS_DELAYABLE_MSG_CTX_ENABLED are both enabled by default, ctx-\u003ernd_delay is set for every received access message, so all replies from Configuration Server, Health Server and application server models are silently dropped. The node keeps receiving and processing traffic but never answers, a persistent denial of service until the device is restarted. There is no memory corruption, information disclosure or integrity impact; releases before the fix compute the chunk count from the transmit buffer capacity rather than its payload length, making chunk-pool starvation — and therefore the leak — considerably easier to provoke.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"Bluetooth Mesh Access layer permanently leaks delayable-message contexts, disabling all model responses","id":"CVE-2026-19937","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"Use-after-free of an ATT PDU buffer when signing an outgoing Bluetooth ATT Signed Write Command fails","id":"CVE-2026-19938"},"packages":[],"prev":{"headline":"Bluetooth Mesh delayable message queue: unsynchronized list access leads to NULL pointer dereference","id":"CVE-2026-19936"},"products":["zephyr"],"published":"2026-10-12","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-14","vendors":["zephyrproject"]},"summary":"A remote attacker can permanently leak message contexts in Zephyr's Bluetooth Mesh, causing a denial of service by disabling all model responses.","url":"https://insights.sbomify.com/CVE-2026-19937/"}