Op TeeOperating system · Trustedfirmware

CVE-2026-44362

MEDIUM · 5.5 CVSS v3.1 Published 2026-07-06
Fix available
A fix is available. Upgrade to after 4.10.0 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click 6 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In OP-TEE versions 3.20.0 through 4.10.x, the function `shdr_load_pub_key()` in `core/crypto/signed_hdr.c` parses subkey headers but fails to assign the parsed `subkey_version` to the runtime `shdr_pub_key` structure's `key->version` field, leaving it at zero. When `ree_fs_ta_open()` calls `check_update_version()` with this zeroed version, the rollback database never advances, allowing TAs signed with revoked or older subkey versions to load successfully.

MitigationUpgrade OP-TEE to version 4.11.0 or later to obtain the patch that properly propagates subkey versioning data during TA loading.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Op TeeOperating system
Affected:>= 3.20.0, <= 4.10.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify OP-TEE version
    Check the build version of OP-TEE running in your environment. This is typically found in the build system (build/_wildcard/versionInfo.c or similar), the manifest, or the debug logs. Common locations include /sys/firmware/devicetree/base/model or from tee-supplicant logs showing the OPTEE version string.
    Affected if The installed version is 3.20.0 through 4.10.0 inclusive.
  2. Confirm subkey TA signing is in use
    Determine if Trusted Applications are signed using subkey-based signing (as opposed to a single root key). This can be verified by examining the TA binary headers or build configuration showing subkey_path or SUBKEY_ parameters in the signing process.
    Affected if TAs are signed with subkeys and loaded through the REE Filesystem (REE_FS) backend.
  3. Locate the vulnerable code path
    Inspect the file core/crypto/signed_hdr.c in your OP-TEE source or binary. Specifically verify whether the function shdr_load_pub_key() assigns subkey_version to key->version. In a binary, this would require symbol inspection or comparing against the fixed version 4.11.0.
    Affected if The shdr_load_pub_key() function does not propagate subkey_version to key->version, leaving it zeroed.
  4. Observe rollback behavior with test TA
    Load a test TA signed with an older subkey version while monitoring the rollback database (rollback.db or similar in secure storage). The version passed to check_update_version() should be non-zero if fixed.
    Affected if The rollback database fails to advance when loading TAs with subkey versions, allowing previously revoked subkey versions to load.

Your environment is affected if OP-TEE version is between 3.20.0 and 4.10.0 inclusive AND you use subkey-signed Trusted Applications loaded via the REE Filesystem, because the unpatched code leaves subkey version as zero and does not advance the rollback protection.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 4.10.0
Interim mitigation

Upgrade OP-TEE to version 4.11.0 or later to obtain the patch that properly propagates subkey versioning data during TA loading.

Recommended fix High confidence

4.11.0

  1. Upgrade OP-TEE to version 4.11.0 or later to resolve the subkey rollback protection vulnerability

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Op Tee Scoped from the published advisory
  • Consultation4.0 h
  • Implementation3.0 h
  • Testing8.0 h
  • Review / QA3.0 h
18.0 hours of engineering $3,080
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,928.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-44362 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-44362 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data