---
id: CVE-2026-71969
title: >-
  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 A…
summary: >-
  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 A…
severity: medium
cvss: 6.7
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-124
  - CWE-787
published: '2026-08-10'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T20:05:09.813'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-71969'
references:
  - url: 'https://blog.secmate.dev/posts/optee-vulnerabilities-disclosure/'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/OP-TEE/optee_os/commit/7b8b494e0a324cefec8ed386b7de413b44f1aaf3
    label: disclosure@vulncheck.com
  - url: 'https://github.com/OP-TEE/optee_os/pull/7808'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/OP-TEE/optee_os/pull/7898'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/op-tee-os-buffer-underwrite-via-rsa-nopad-encrypt-decrypt-operations
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00182
epssPercentile: 0.06914
ingestedAt: '2026-09-24T20:51:40.189Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.