{"id":"CVE-2026-10635","aliases":["EUVD-2026-37036","GHSA-39v7-cx8j-gq82"],"status":"published","title":"Dangling memory-domain pointer (use-after-free) in Xtensa MMU page-table code on memory-domain de-init","description":"On Xtensa targets with CONFIG_USERSPACE and CONFIG_XTENSA_MMU, the page-table code (arch/xtensa/core/ptables.c) maintains a global list, xtensa_domain_list, of active memory domains using a list node embedded inside the caller-owned struct k_mem_domain. When a domain is destroyed via k_mem_domain_deinit() -\u003e arch_mem_domain_deinit(), the page tables are torn down and domain-\u003earch.ptables is set to NULL, but the domain's node was not removed from xtensa_domain_list. The freed/deinitialized domain therefore remained linked into the global list as a dangling pointer into caller-owned storage that may then be freed or reused.\n\nAny subsequent arch_mem_map()/arch_mem_unmap() operation (widely invoked by kernel memory-mapping and demand-paging code) traverses the stale node and dereferences domain-\u003eptables: at minimum a NULL pointer dereference causing a fatal MMU exception (denial of service), and if the k_mem_domain storage has been freed or reused, a use-after-free in which a stale/controlled ptables value is dereferenced and written through during the page-table walk (l2_page_table_map writes l1_table[...] and l2_table[...], and xtensa_mmu_compute_domain_regs writes into the domain struct and the L1 table), yielding page-table memory corruption that can undermine userspace isolation.\n\nThe vulnerable path is reachable only from privileged kernel/supervisor code (k_mem_domain_deinit is not a syscall), not directly from unprivileged user threads or remotely. Affected: Zephyr v4.4.0 (the Xtensa memory-domain de-initialization feature was introduced in commit 3032b58f52d and first shipped in v4.4.0); fixed on main by adding sys_slist_find_and_remove() in arch_mem_domain_deinit(). The Xtensa MPU path is unaffected.","severity":{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00164,"percentile":0.05613,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-416"],"published":"2026-06-16T05:19:20Z","modified":"2026-10-28T10:46:00Z","products":[{"vendor":"zephyrproject","product":"zephyr"},{"vendor":"zephyrproject-rtos","product":"zephyr"}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/33d43d09337119fc6084b4ab545f9267839973f6","tags":["patch","Patch","fix"]},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-39v7-cx8j-gq82","tags":["Exploit","Patch","Vendor Advisory","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/10xxx/CVE-2026-10635.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-10635","tags":["advisory"]},{"url":"https://github.com/zephyrproject-rtos/zephyr","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-10635","title":"Dangling memory-domain pointer (use-after-free) in Xtensa MMU page-table code on memory-domain de-init","description":"On Xtensa targets with CONFIG_USERSPACE and CONFIG_XTENSA_MMU, the page-table code (arch/xtensa/core/ptables.c) maintains a global list, xtensa_domain_list, of active memory domains using a list node embedded inside the caller-owned struct k_mem_domain. When a domain is destroyed via k_mem_domain_deinit() -\u003e arch_mem_domain_deinit(), the page tables are torn down and domain-\u003earch.ptables is set to NULL, but the domain's node was not removed from xtensa_domain_list. The freed/deinitialized domain therefore remained linked into the global list as a dangling pointer into caller-owned storage that may then be freed or reused.\n\nAny subsequent arch_mem_map()/arch_mem_unmap() operation (widely invoked by kernel memory-mapping and demand-paging code) traverses the stale node and dereferences domain-\u003eptables: at minimum a NULL pointer dereference causing a fatal MMU exception (denial of service), and if the k_mem_domain storage has been freed or reused, a use-after-free in which a stale/controlled ptables value is dereferenced and written through during the page-table walk (l2_page_table_map writes l1_table[...] and l2_table[...], and xtensa_mmu_compute_domain_regs writes into the domain struct and the L1 table), yielding page-table memory corruption that can undermine userspace isolation.\n\nThe vulnerable path is reachable only from privileged kernel/supervisor code (k_mem_domain_deinit is not a syscall), not directly from unprivileged user threads or remotely. Affected: Zephyr v4.4.0 (the Xtensa memory-domain de-initialization feature was introduced in commit 3032b58f52d and first shipped in v4.4.0); fixed on main by adding sys_slist_find_and_remove() in arch_mem_domain_deinit(). The Xtensa MPU path is unaffected.","status":"published","published":"2026-06-16T05:19:20.487Z","modified":"2026-10-15T22:10:00.085Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-416"],"updated_at":"2026-11-02T13:40:12.486331Z"}],"euvd":[{"id":"EUVD-2026-37036","description":"On Xtensa targets with CONFIG_USERSPACE and CONFIG_XTENSA_MMU, the page-table code (arch/xtensa/core/ptables.c) maintains a global list, xtensa_domain_list, of active memory domains using a list node embedded inside the caller-owned struct k_mem_domain. When a domain is destroyed via k_mem_domain_deinit() -\u003e arch_mem_domain_deinit(), the page tables are torn down and domain-\u003earch.ptables is set to NULL, but the domain's node was not removed from xtensa_domain_list. The freed/deinitialized domain therefore remained linked into the global list as a dangling pointer into caller-owned storage that may then be freed or reused.\n\nAny subsequent arch_mem_map()/arch_mem_unmap() operation (widely invoked by kernel memory-mapping and demand-paging code) traverses the stale node and dereferences domain-\u003eptables: at minimum a NULL pointer dereference causing a fatal MMU exception (denial of service), and if the k_mem_domain storage has been freed or reused, a use-after-free in which a stale/controlled ptables value is dereferenced and written through during the page-table walk (l2_page_table_map writes l1_table[...] and l2_table[...], and xtensa_mmu_compute_domain_regs writes into the domain struct and the L1 table), yielding page-table memory corruption that can undermine userspace isolation.\n\nThe vulnerable path is reachable only from privileged kernel/supervisor code (k_mem_domain_deinit is not a syscall), not directly from unprivileged user threads or remotely. Affected: Zephyr v4.4.0 (the Xtensa memory-domain de-initialization feature was introduced in commit 3032b58f52d and first shipped in v4.4.0); fixed on main by adding sys_slist_find_and_remove() in arch_mem_domain_deinit(). The Xtensa MPU path is unaffected.","status":"published","published":"2026-06-16T05:19:20Z","modified":"2026-10-15T22:10:00Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:H","level":"medium"}],"updated_at":"2026-11-02T17:00:07.251605Z"}],"nvd":[{"id":"CVE-2026-10635","description":"On Xtensa targets with CONFIG_USERSPACE and CONFIG_XTENSA_MMU, the page-table code (arch/xtensa/core/ptables.c) maintains a global list, xtensa_domain_list, of active memory domains using a list node embedded inside the caller-owned struct k_mem_domain. When a domain is destroyed via k_mem_domain_deinit() -\u003e arch_mem_domain_deinit(), the page tables are torn down and domain-\u003earch.ptables is set to NULL, but the domain's node was not removed from xtensa_domain_list. The freed/deinitialized domain therefore remained linked into the global list as a dangling pointer into caller-owned storage that may then be freed or reused.\n\nAny subsequent arch_mem_map()/arch_mem_unmap() operation (widely invoked by kernel memory-mapping and demand-paging code) traverses the stale node and dereferences domain-\u003eptables: at minimum a NULL pointer dereference causing a fatal MMU exception (denial of service), and if the k_mem_domain storage has been freed or reused, a use-after-free in which a stale/controlled ptables value is dereferenced and written through during the page-table walk (l2_page_table_map writes l1_table[...] and l2_table[...], and xtensa_mmu_compute_domain_regs writes into the domain struct and the L1 table), yielding page-table memory corruption that can undermine userspace isolation.\n\nThe vulnerable path is reachable only from privileged kernel/supervisor code (k_mem_domain_deinit is not a syscall), not directly from unprivileged user threads or remotely. Affected: Zephyr v4.4.0 (the Xtensa memory-domain de-initialization feature was introduced in commit 3032b58f52d and first shipped in v4.4.0); fixed on main by adding sys_slist_find_and_remove() in arch_mem_domain_deinit(). The Xtensa MPU path is unaffected.","status":"published","published":"2026-06-16T06:16:57.77Z","modified":"2026-10-25T23:10:00.167Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:H","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:H","level":"medium","assessor":"primary"}],"cwes":["CWE-416"],"updated_at":"2026-11-02T14:12:24.19758Z"}],"osv":[{"id":"CVE-2026-10635","title":"Dangling memory-domain pointer (use-after-free) in Xtensa MMU page-table code on memory-domain de-init","description":"On Xtensa targets with CONFIG_USERSPACE and CONFIG_XTENSA_MMU, the page-table code (arch/xtensa/core/ptables.c) maintains a global list, xtensa_domain_list, of active memory domains using a list node embedded inside the caller-owned struct k_mem_domain. When a domain is destroyed via k_mem_domain_deinit() -\u003e arch_mem_domain_deinit(), the page tables are torn down and domain-\u003earch.ptables is set to NULL, but the domain's node was not removed from xtensa_domain_list. The freed/deinitialized domain therefore remained linked into the global list as a dangling pointer into caller-owned storage that may then be freed or reused.\n\nAny subsequent arch_mem_map()/arch_mem_unmap() operation (widely invoked by kernel memory-mapping and demand-paging code) traverses the stale node and dereferences domain-\u003eptables: at minimum a NULL pointer dereference causing a fatal MMU exception (denial of service), and if the k_mem_domain storage has been freed or reused, a use-after-free in which a stale/controlled ptables value is dereferenced and written through during the page-table walk (l2_page_table_map writes l1_table[...] and l2_table[...], and xtensa_mmu_compute_domain_regs writes into the domain struct and the L1 table), yielding page-table memory corruption that can undermine userspace isolation.\n\nThe vulnerable path is reachable only from privileged kernel/supervisor code (k_mem_domain_deinit is not a syscall), not directly from unprivileged user threads or remotely. Affected: Zephyr v4.4.0 (the Xtensa memory-domain de-initialization feature was introduced in commit 3032b58f52d and first shipped in v4.4.0); fixed on main by adding sys_slist_find_and_remove() in arch_mem_domain_deinit(). The Xtensa MPU path is unaffected.","status":"published","published":"2026-06-16T05:19:20.487Z","modified":"2026-10-28T10:46:00.095112525Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:H","level":"medium"}],"cwes":["CWE-416"],"updated_at":"2026-11-02T15:44:54.583213Z"}]}}