CVE-2026-44362
OP-TEE's subkey rollback protection can be bypassed with older subkey versions
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.
INFO
Published Date :
July 6, 2026, 8:16 p.m.
Last Modified :
Oct. 25, 2026, 8:10 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update OP-TEE to version 4.11.0 or later.
- Verify TA integrity after update.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-44362.
| URL | Resource |
|---|---|
| https://github.com/OP-TEE/optee_os/security/advisories/GHSA-fhcg-pp56-8v75 | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-44362 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-44362
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-44362 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-44362 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Translated by [email protected]
Oct. 25, 2026
Action Type Old Value New Value Added Translation Title: optee_os de OP-TEE, Description: OP-TEE es un Entorno de Ejecución Confiable (TEE) diseñado como compañero de un kernel de Linux no seguro ejecutándose en núcleos Arm Cortex-A utilizando la tecnología TrustZone. A partir de la versión 3.20.0 y anterior a la versión 4.11.0, una vulnerabilidad en la protección de reversión de subclave de OP-TEE permite el uso de versiones de subclave revocadas o más antiguas porque el sistema no propaga los datos de versionado durante el proceso de carga de la Aplicación Confiable (TA). En ’core/crypto/signed_hdr.c’, la función ’shdr_load_pub_key()’ analiza los encabezados de subclave pero no asigna la ’subkey_version’ a la estructura ’shdr_pub_key’ en tiempo de ejecución. Como resultado, el campo ’key -> version’ permanece en cero independientemente de la versión especificada en el encabezado. Cuando ’ree_fs_ta_open()’ en ’core/kernel/ree_fs_ta.c’ llama a ’check_update_version()’, pasa esta versión puesta a cero a la base de datos de reversión. Debido a que la base de datos nunca recibe una versión no nula para registrar, nunca avanza, eludiendo efectivamente la verificación de reversión y permitiendo que las TA firmadas con cadenas de subclaves degradadas se carguen correctamente. Esto afecta a las configuraciones principales de OP-TEE que utilizan cadenas de firma basadas en subclaves para la autenticación de Aplicaciones Confiables (TA). La versión 4.11.0 contiene un parche. No se conocen soluciones alternativas disponibles. -
Initial Analysis by [email protected]
Jul. 07, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:o:trustedfirmware:op-tee:*:*:*:*:*:*:*:* versions from (including) 3.20.0 up to (including) 4.10.0 Added Reference Type GitHub, Inc.: https://github.com/OP-TEE/optee_os/security/advisories/GHSA-fhcg-pp56-8v75 Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 06, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-44362', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-06T20:51:43.694755Z'} -
New CVE Received by [email protected]
Jul. 06, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'OP-TEE', 'product': 'optee_os', 'versions': [{'status': 'affected', 'version': '>= 3.20.0, < 4.11.0'}]}] Added 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. Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Added CWE CWE-285 Added Reference https://github.com/OP-TEE/optee_os/security/advisories/GHSA-fhcg-pp56-8v75