# CVE-2026-71969

## Summary

- **CVE ID:** CVE-2026-71969
- **Severity:** HIGH
- **CVSS Score:** 8.4 (CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N)
- **CWE:** CWE-787, CWE-124
- **Published:** Aug 10, 2026
- **Last Modified:** Aug 17, 2026

## Description

OP-TEE OS through 4.10.0, fixed in commit 7b8b494, contains a buffer underwrite vulnerability in the RSA NOPAD encrypt and decrypt operations within the mbedTLS software backend and SE050 hardware driver that allows a malicious Trusted Application to corrupt secure-world heap memory by supplying an input length exceeding the RSA modulus size. When src_len exceeds rsa_len, the subtraction expression wraps to a large unsigned value, causing a subsequent memcpy to write attacker-controlled data before the destination buffer in S-EL1 secure-world heap memory.

## Affected Products

- OP-TEE — optee_os (0)
- OP-TEE — optee_os (7b8b494e0a324cefec8ed386b7de413b44f1aaf3)

## References

- [CNA](https://github.com/OP-TEE/optee_os/pull/7898)
- [CNA](https://github.com/OP-TEE/optee_os/pull/7808)
- [CNA](https://github.com/OP-TEE/optee_os/commit/7b8b494e0a324cefec8ed386b7de413b44f1aaf3)
- [CNA](https://www.vulncheck.com/advisories/op-tee-os-buffer-underwrite-via-rsa-nopad-encrypt-decrypt-operations)
- [CNA](https://blog.secmate.dev/posts/optee-vulnerabilities-disclosure/)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.13%
- **EPSS Percentile:** 3.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._