{"id":"CVE-2026-95108","title":"Deleting a user-mode module thread leaks its privileged kernel stack","summary":"One logical thread of a user-mode ThreadX module costs the Module Manager's shared object pool two allocations, not one. The module asks for a `TX_THREAD` control block through `txm_module_object_allocate`; `_txm_module_manager_thread_cr…","severity":"medium","cvss":6.8,"cvssVector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","cvssSource":"cna","cwe":["CWE-400","CWE-772"],"vendor":"Eclipse Foundation","product":"ThreadX","affected":["ThreadX >= 6.0.1 <= 6.5.1.202602a"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-20T17:05:59.302618Z"},"published":"2026-10-20","updated":"2026-10-20","sourceUpdated":"2026-10-20T17:06:10.079Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-95108","references":[{"url":"https://github.com/eclipse-threadx/threadx/security/advisories/GHSA-9hhf-6357-hpgq"}],"tags":["cve.org"],"ingestedAt":"2026-10-20T16:10:53.315Z","slug":"CVE-2026-95108","body":"## Overview\n\nOne logical thread of a user-mode ThreadX module costs the Module Manager's shared object pool two allocations, not one. The module asks for a `TX_THREAD` control block through `txm_module_object_allocate`; `_txm_module_manager_thread_create` then takes a second allocation of `TXM_MODULE_KERNEL_STACK_SIZE` bytes for the privileged kernel stack that thread's system calls run on, and records it in the control block. Both come from `_txm_module_manager_object_pool` and both are linked onto the module's allocation list.\n\n\n\nThe Module Manager's thread-delete dispatcher released only the first. The kernel stack stayed allocated until the whole module was stopped, so a module that creates, terminates and deletes threads in a loop — every state transition valid, every service returning `TX_SUCCESS` — removed a fixed block from a finite pool shared by the manager and by every other loaded module, on every cycle, for as long as it stayed loaded. Once the pool is exhausted, no memory-protected module can create any kernel object and no user-mode module thread can be created anywhere in the system.\n\n\n\nVulnerable function: `_txm_module_manager_tx_thread_delete_dispatch`, in `common_modules/module_manager/inc/txm_module_manager_dispatch.h`.\n\n## Affected\n\n- `ThreadX >= 6.0.1 <= 6.5.1.202602a`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":37,"depthScoreParts":{"impact":37.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}