OP-TEE has missing OPTEE_MSG_ATTR_TYPE_MASK in cleanup_shm_refs() leaks mobj references
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-770.
Summary
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 3.3.0 and prior to version 4.11.0, a resource leak exists in OP-TEE’s shared memory cleanup logic because the function `cleanup_shm_refs()` in `core/tee/entry_std.c` fails to apply a required bitmask (`OPTEE_MSG_ATTR_TYPE_MASK`) to parameter attributes. When processing non-contiguous memory parameters from a normal-world caller, the system fails to match the attribute type in its internal switch statement and skips the necessary mobj_put() call. This results in a persistent reference leak of `mobj_reg_shm` objects, which remain on internal lists with dangling refcounts. This affects non-FF-A configurations that support non-contiguous, non-secure shared memory. Over time, these accumulated leaks progressively consume the secure-world heap, degrading the system's ability to service trusted application operations and eventually requiring a reboot to recover. Version 4.11.0 contains a patch. No known workarounds are available.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA optee_os (OP-TEE) Fixed in 4.11.0
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2026-42546
References
More Op-tee vulnerabilities
- TI-2022-22796 OP-TEE Trusted OS vulnerable to Improper Validation of Array Index in the cleanup_shm_refs function CVSS 3.1HIGH 8.8
- TI-2026-29072 OP-TEE has a Use-After-Free race in FF-A shared-memory teardown CVSS 3.1HIGH 7.8
- TI-2023-21925 OP-TEE double free in shdr_verify_signature CVSS 3.1HIGH 7.4
- TI-2026-33359 OP-TEE vulnerable to ECDH private key recovery CVSS 3.1MEDIUM 4.7
- TI-2019-16063 Integer overflow in OP-TEE CVSS 3.0CRITICAL 9.8
- TI-2019-16062 Integer overflow in OP-TEE CVSS 3.0CRITICAL 9.8
Sources
- CVE-2026-42546 · CVE Program
- CVE-2026-42546 · NVD
- FIRST EPSS
- CVE-2026-42546 · Red Hat security data · CC BY 4.0
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