CVE-2026-44362 OP-TEE's subkey rollback protection can be bypassed with older subkey versions
Attackers can bypass subkey rollback protection in OP-TEE by loading Trusted Applications signed with revoked or older subkeys, undermining secure boot integrity.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-44362?
CVE-2026-44362 is a medium-severity vulnerability in OP-TEE optee_os, published on 6 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-285
Which versions are affected by CVE-2026-44362?
It affects 1 product.
Products include Trustedfirmware Op-Tee.
How do I fix CVE-2026-44362?
No fix has been published for CVE-2026-44362 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-44362 being exploited?
There is no known exploitation of CVE-2026-44362 in the wild and no public exploit code.
Other vulnerabilities in OP-TEE optee_os
Sources
Also known as DEBIAN-CVE-2026-44362, GHSA-fhcg-pp56-8v75, UBUNTU-CVE-2026-44362.