PT-2026-55976 · Op Tee · Optee Os
Published
2026-07-06
·
Updated
2026-07-06
·
CVE-2026-44362
CVSS v3.1
5.5
Medium
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N |
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 3.20.0 and prior to version 4.11.0, a vulnerability in OP-TEE’s subkey rollback protection allows the use of revoked or older subkey versions because the system fails to propagate versioning data during the Trusted Application (TA) loading process. In
core/crypto/signed hdr.c, the function shdr load pub key() parses subkey headers but does not assign the subkey version to the runtime shdr pub key structure. As a result, the key->version field remains at zero regardless of the version specified in the header. When ree fs ta open() in core/kernel/ree fs ta.c calls check update version(), it passes this zeroed version to the rollback database. Because the database never receives a non-zero version to record, it never advances, effectively bypassing the rollback check and allowing TAs signed with downgraded subkey chains to load successfully. This impacts OP-TEE mainline configurations that utilize subkey-based signing chains for Trusted Application (TA) authentication. Version 4.11.0 contains a patch. No known workarounds are available.Fix
Improper Authorization
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Weakness Enumeration
Related Identifiers
Affected Products
Optee Os