{"id":"CVE-2026-44362","summary":"OP-TEE's subkey rollback protection can be bypassed with older subkey versions","details":"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-\u003eversion` 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.","aliases":["GHSA-fhcg-pp56-8v75"],"modified":"2026-10-21T02:52:34.894153001Z","published":"2026-07-06T19:33:48.666Z","database_specific":{"cwe_ids":["CWE-285"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44362.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44362.json"},{"type":"ADVISORY","url":"https://github.com/OP-TEE/optee_os/security/advisories/GHSA-fhcg-pp56-8v75"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44362"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/op-tee/optee_os","events":[{"introduced":"8e74d47616a20eaa23ca692f4bbbf917a236ed94"},{"fixed":"f54190f22611dd5ad5d22546fd4209aa100f56bd"}],"database_specific":{"extracted_events":[{"strategy":"StringRangeExpression","range":[{"introduced":"3.20.0"},{"fixed":"4.11.0"}],"source":"AFFECTED_FIELD"}]}}],"versions":["4.11.0-rc1","4.10.0","4.10.0-rc1","4.9.0","4.9.0-rc1","4.8.0","4.8.0-rc1","4.7.0","4.7.0-rc1","4.6.0","4.6.0-rc1","4.5.0","4.5.0-rc1","4.4.0","4.4.0-rc1","4.3.0","4.3.0-rc1","4.2.0","4.2.0-rc1","4.1.0","4.1.0-rc1","4.0.0","4.0.0-rc1","3.22.0","3.22.0-rc1","3.21.0","3.21.0-rc1","3.20.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-44362.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N"}]}