{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-10681 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-10681 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-10681 is a medium-severity vulnerability in Zephyrproject Zephyr, published on 25 Jul 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-2026-10681 and fix it if it is affected.\n\nWhat it is: CVE-2026-10681 is a medium-severity vulnerability in Zephyrproject Zephyr, published on 25 Jul 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-2026-10681 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-2026-10681/ (Markdown: https://insights.sbomify.com/CVE-2026-10681/index.md)","id":"CVE-2026-10681","markdown":"https://insights.sbomify.com/CVE-2026-10681/index.md","name":"CVE-2026-10681","record":{"aliases":["GHSA-j693-5rh5-8g8h"],"analysis":{"component_type":"operating_system","fix_type":"patch","impacts":["privilege_escalation","security_bypass"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Zephyr RTOS","requires_auth":"low_privilege","summary":"Concurrent thread allocation in Zephyr RTOS allows user threads to share permission slots, bypassing kernel object access controls and enabling privilege escalation.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"zephyr","cpe":[{"product":"zephyr","vendor":"zephyrproject"}],"cvss":{"score":6.5,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L","version":"3.1"},"cwes":[{"id":"CWE-362","name":"Concurrent Execution using Shared Resource with Improper Synchronization"}],"description":"In Zephyr's userspace dynamic-objects subsystem, thread_idx_alloc() in kernel/userspace/userspace.c allocated a new thread permission index from the global _thread_idx_map[] bitmap without holding lists_lock.\n\nOn SMP systems, two user-mode threads invoking the k_object_alloc(K_OBJ_THREAD) syscall concurrently can both observe the same low free bit, perform the same non-atomic RMW to clear it, and return the identical tidx.\n\nThe two newly created K_OBJ_THREAD objects are then assigned the same thread_id, so the two user threads alias a single bit position in every kernel object's perms[] bitfield: any subsequent grant of access on a kernel object to one thread is implicitly a grant to the other, defeating userspace ACL isolation. A secondary lost-update window between the unlocked \u0026=~BIT() in alloc and the locked |= BIT() in thread_idx_free() can also leak entries from the thread-index pool.\n\nThe defect is reachable from any user-mode thread via the unrestricted __syscall k_object_alloc and is gated on CONFIG_USERSPACE, CONFIG_DYNAMIC_OBJECTS, and CONFIG_SMP. The flaw was introduced when the per-thread permission index was added in 2018 and is present in every release up to and including v4.4.0. Fixed by holding lists_lock across the bitmap RMW and the permissions clear (and inlining the obj_list traversal that previously took the lock itself).","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":"Race condition in zephyr","id":"CVE-2026-10681","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"zephyrproject:zephyr","products":["zephyrproject:zephyr"],"type":"race_condition","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"Out-of-bounds write in Zephyr `log_filter_set` syscall verifier reachable from userspace","id":"CVE-2026-10682"},"packages":[],"prev":{"headline":"Out-of-bounds access in Zephyr BR/EDR L2CAP configuration request handling via `uint16_t` length underflow","id":"CVE-2026-10680"},"products":["zephyr"],"published":"2026-07-25","related":[{"cvss_score":9.8,"headline":"Out-of-bounds read/write in HTTP WebSocket upgrade via non-null-terminated Sec-WebSocket-Key","id":"CVE-2026-5067","kev_date_added":null,"published":"2026-06-09"},{"cvss_score":9.8,"headline":"Bluetooth HCI Error Handling Double Free","id":"CVE-2022-3806","kev_date_added":null,"published":"2023-01-19"},{"cvss_score":9.8,"headline":"Memory corruption in getaddrinfo","id":"CVE-2017-14199","kev_date_added":null,"published":"2019-04-12"},{"cvss_score":9.8,"headline":"Null dereference in n/a","id":"CVE-2018-1000800","kev_date_added":null,"published":"2018-09-06"},{"cvss_score":9.6,"headline":"DOS: Incorrect handling of the initial HCI ACL_MTU handshake packet leads to crash of bluetooth host layer","id":"CVE-2021-3329","kev_date_added":null,"published":"2023-02-26"},{"cvss_score":9.6,"headline":"DoS: Invalid Initialization in le_read_buffer_size_complete","id":"CVE-2023-0397","kev_date_added":null,"published":"2023-01-19"},{"cvss_score":9.6,"headline":"Usb bluetooth device ACL read cb buffer overflow","id":"CVE-2021-3966","kev_date_added":null,"published":"2023-01-11"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"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":"total"},"state":"PUBLISHED","updated":"2026-10-15","vendors":["zephyrproject"]},"summary":"Concurrent thread allocation in Zephyr RTOS allows user threads to share permission slots, bypassing kernel object access controls and enabling privilege escalation.","url":"https://insights.sbomify.com/CVE-2026-10681/"}