CVE-2026-40290 remediation guide
OP-TEE optee_os, op-tee
OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 3.16.0 and prior to 4.11.0, a user-after-free (UAF) race condition exists in the shared memory teardown logic of FF-A within OP-TEE SPMC/SP flows. This only applies when OP-TEE is configured as an SPMC for S-EL0 SPs, that is, with `CFG_SECURE_PARTITION=y`. The function `sp_mem_remove()`, responsible for freeing entries in `smem->receivers` and `smem->regions`, fails to acquire the global `sp_mem_lock` before per...
A verified fixed-version field is not available. Use the linked NVD and supporting references, then confirm the vendor-supported path before changing production systems.
Identify the affected asset
Confirm whether OP-TEE optee_os, op-tee is installed, record the deployed version and installation path, and identify exposed interfaces.
- Record the product name, package or appliance identifier, and installed version.
- Identify internet-facing, administrative, API, and internal access paths.
- Preserve the pre-change configuration and relevant service logs.
Validate the affected-version match
Compare the deployed version with the affected range: >= >= 3.16.0, < 4.11.0, >= 3.16.0 <= 4.10.0. Treat incomplete inventory results as unresolved.
Prioritize with independent signals
The CVSS severity warrants an early asset and exposure review. Combine this signal with asset criticality, exposure, compensating controls, and business impact.
Apply supported remediation
Follow the vendor advisory or supported update path. Current fixed-version status: No verified fixed-version field is available yet. Preserve configuration and rollback material before change.
Verify the result
Confirm the resulting version, service health, authentication and access paths, monitoring coverage, and relevant security logs.
- Confirm the expected version and package state.
- Run a functional health check for critical service paths.
- Review authentication, error, application, and security monitoring logs.
- Reassess exposure if the supported fix cannot be applied.
Operational boundary
This page does not replace the vendor advisory, support contract, change-management process, or recovery plan. Do not infer that an asset is unaffected from an incomplete inventory query or a missing fixed-version field.