CVE-2026-95108
Deleting a user-mode module thread leaks its privileged kernel stack
Published Oct 20, 2026
CVSS 4.0 · 6.8 Medium
EPSS < 1%
KEV · Not listed
Description
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_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.
The 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.
Vulnerable function: `_txm_module_manager_tx_thread_delete_dispatch`, in `common_modules/module_manager/inc/txm_module_manager_dispatch.h`.
The 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.
Vulnerable function: `_txm_module_manager_tx_thread_delete_dispatch`, in `common_modules/module_manager/inc/txm_module_manager_dispatch.h`.
Affected Products
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CVE record
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NVD configurations
No data
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Red Hat packages
No data
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OpenCVE enrichment
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||
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| Eclipse Foundation | Eclipse ThreadX | unaffected |
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| Eclipse | Threadx |
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Remediation
Tracking
Advisories
Metrics
Attack Vector Local
Attack Complexity Low
Privileges Required Low
Attack Requirements None
User Interaction None
Vulnerable System Confidentiality Impact None
Vulnerable System Integrity Impact None
Vulnerable System Availability Impact High
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
No CVSS v3.1
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.171% probability within 30 days)
Exploitation none
Automatable no
Technical Impact partial
References
History
Oct 20, 2026 9:00 PM
First appearance in the feed. Affected vendors updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Eclipse
Eclipse threadx |
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| Vendors & Products |
Eclipse
Eclipse threadx |
Oct 20, 2026 5:30 PM
Scoring metrics updated
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| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Oct 20, 2026 3:30 PM
Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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_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. The 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. Vulnerable function: `_txm_module_manager_tx_thread_delete_dispatch`, in `common_modules/module_manager/inc/txm_module_manager_dispatch.h`. | |
| Title | Deleting a user-mode module thread leaks its privileged kernel stack | |
| Weaknesses | CWE-400 CWE-772 |
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| References |
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| Metrics |
cvssV4_0
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