The vulnerability CVE-2026-41514 in OP-TEE's optee_os affects the RSA-OAEP decryption in the Hisilicon HPRE crypto driver on plat-d06 with CFG_HISILICON_ACC_V3 enabled. The implementation uses a non-constant-time memcmp() for label hash verification and has multiple error paths that differ in timing, enabling a Manger-style padding oracle attack. This allows an attacker with local access to recover RSA-OAEP plaintext after approximately 1000-2000 adaptive chosen ciphertext queries. The vulnerability is fixed in version 4.11.0. The affected configuration is disabled by default, reducing exposure. A workaround is to disable the Hisilicon HPRE RSA driver by setting CFG_HISILICON_ACC_V3 to n.

An attacker with local access and low privileges can exploit the timing discrepancy in RSA-OAEP decryption to recover plaintext from ciphertext using a Manger-style padding oracle attack. The impact is limited to confidentiality (partial plaintext recovery) with no integrity or availability impact. The attack requires a high level of access control and multiple adaptive queries, limiting practical exploitation. The affected configuration is disabled by default, further reducing risk.

Version 4.11.0 of OP-TEE contains a patch that fixes this vulnerability. Users should upgrade to version 4.11.0 or later. As a workaround, if upgrading is not immediately possible, disable the Hisilicon HPRE RSA driver by setting CFG_HISILICON_ACC_V3=n to prevent exposure. Since the affected configuration is disabled by default, verify the configuration to ensure it is not enabled. Patch status is not explicitly confirmed beyond the mention of version 4.11.0 containing a fix; check the vendor advisory for the latest remediation guidance.