CVE-2026-41515: CWE-208: Observable Timing Discrepancy in OP-TEE optee_os
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 3.9.0 and prior to version 4.11.0, the RSA-OAEP decryption implementation in the NXP CAAM crypto driver uses non-constant-time `memcmp()` for label hash verification and has multiple distinguishable error paths. This creates a Manger-style padding oracle that allows an attacker to recover RSA-OAEP plaintext with approximately 1000-2000 adaptive chosen ciphertext queries. Version 4.11.0 contains a patch. As a workaround, disable the NXP CAAM RSA driver with `CFG_CRYPTO_DRV_RSA=n`.
AI Analysis
Technical Summary
The OP-TEE Trusted Execution Environment's RSA-OAEP decryption in the NXP CAAM crypto driver uses a non-constant-time memcmp() for label hash verification and has multiple error paths that differ in observable timing. This creates a Manger-style padding oracle vulnerability allowing an attacker to recover plaintext from ciphertext with around 1000-2000 adaptive chosen ciphertext queries. The vulnerability affects versions >=3.9.0 and <4.11.0. The issue is fixed in version 4.11.0. A workaround is to disable the NXP CAAM RSA driver by setting CFG_CRYPTO_DRV_RSA=n.
Potential Impact
An attacker with local access and the ability to submit adaptive chosen ciphertexts can exploit timing discrepancies to recover RSA-OAEP plaintext data. The confidentiality of RSA-encrypted data is compromised. There is no impact on integrity or availability. The CVSS score is low (2.5) reflecting the requirement for local access, high attack complexity, and limited impact scope.
Mitigation Recommendations
A patch is available in OP-TEE version 4.11.0 that fixes this vulnerability. Users should upgrade to version 4.11.0 or later. As a temporary workaround, the NXP CAAM RSA driver can be disabled by setting CFG_CRYPTO_DRV_RSA=n in the build configuration. No other mitigations are specified.
CVE-2026-41515: CWE-208: Observable Timing Discrepancy in OP-TEE optee_os
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 3.9.0 and prior to version 4.11.0, the RSA-OAEP decryption implementation in the NXP CAAM crypto driver uses non-constant-time `memcmp()` for label hash verification and has multiple distinguishable error paths. This creates a Manger-style padding oracle that allows an attacker to recover RSA-OAEP plaintext with approximately 1000-2000 adaptive chosen ciphertext queries. Version 4.11.0 contains a patch. As a workaround, disable the NXP CAAM RSA driver with `CFG_CRYPTO_DRV_RSA=n`.
CVSS v3.1
Score 2.5low
Affected software
pkg:github/op-tee/optee_osRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The OP-TEE Trusted Execution Environment's RSA-OAEP decryption in the NXP CAAM crypto driver uses a non-constant-time memcmp() for label hash verification and has multiple error paths that differ in observable timing. This creates a Manger-style padding oracle vulnerability allowing an attacker to recover plaintext from ciphertext with around 1000-2000 adaptive chosen ciphertext queries. The vulnerability affects versions >=3.9.0 and <4.11.0. The issue is fixed in version 4.11.0. A workaround is to disable the NXP CAAM RSA driver by setting CFG_CRYPTO_DRV_RSA=n.
Potential Impact
An attacker with local access and the ability to submit adaptive chosen ciphertexts can exploit timing discrepancies to recover RSA-OAEP plaintext data. The confidentiality of RSA-encrypted data is compromised. There is no impact on integrity or availability. The CVSS score is low (2.5) reflecting the requirement for local access, high attack complexity, and limited impact scope.
Mitigation Recommendations
A patch is available in OP-TEE version 4.11.0 that fixes this vulnerability. Users should upgrade to version 4.11.0 or later. As a temporary workaround, the NXP CAAM RSA driver can be disabled by setting CFG_CRYPTO_DRV_RSA=n in the build configuration. No other mitigations are specified.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-20T18:18:50.681Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4c076827e9c7971920cb9a
Added to database: 07/06/2026, 19:52:08 UTC
Last enriched: 07/14/2026, 08:59:04 UTC
Last updated: 08/20/2026, 22:52:12 UTC
Views: 57
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