Vulnerability 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. From 3.8.0 to 4.10, in the function emsa_pkcs1_v1_5_encode() in core/drivers/crypto/crypto_api/acipher/rsassa.c, the amount of padding needed, "PS size", is calculated by subtracting the size of the digest and other fields required for the EMA-PKCS1-v1_5 encoding from the size of the modulus of the key. By selecting a small enough modulus, this subtraction can overflow. The padding is added as a string of 0xFF bytes with a call to memset(), and an underflowed integer will cause the memset() call to overwrite until OP-TEE crashes. This only affects platforms registering RSA acceleration.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linaro | Op-Tee | >= 3.8.0, <= 4.10.0 |
Related Weaknesses (CWE)
References
- https://github.com/OP-TEE/optee_os/security/advisories/GHSA-4cf8-v5g3-73grVendor AdvisoryPatch
FAQ
What is CVE-2026-33662?
CVE-2026-33662 is a vulnerability with a CVSS score of 7.5 (HIGH). 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. From 3.8.0 to 4.10, in the function em...
How severe is CVE-2026-33662?
CVE-2026-33662 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-33662?
Check the references section above for vendor advisories and patch information. Affected products include: Linaro Op-Tee.