---
id: CVE-2026-71967
title: >-
  OP-TEE OS through 4.10.0, fixed in commit 0aadfc2, contains a null pointer
  dereference vulnerability in the Widevine pseudo-TA open_session handler that
  allows Normal World clients to cause a denial of service when CFG_WIDEVINE_PTA
  is en…
summary: >-
  OP-TEE OS through 4.10.0, fixed in commit 0aadfc2, contains a null pointer
  dereference vulnerability in the Widevine pseudo-TA open_session handler that
  allows Normal World clients to cause a denial of service when CFG_WIDEVINE_PTA
  is en…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
published: '2026-08-10'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T20:32:21.400'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-71967'
references:
  - url: >-
      https://github.com/OP-TEE/optee_os/commit/0aadfc23407f50e770eb5ddd871fc208f5626833
    label: disclosure@vulncheck.com
  - url: 'https://github.com/OP-TEE/optee_os/pull/7899'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/op-tee-os-null-pointer-dereference-dos-via-widevine-pta-open-session
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.0017
epssPercentile: 0.05528
ingestedAt: '2026-09-16T21:05:36.837Z'
---

## Overview

OP-TEE OS through 4.10.0, fixed in commit 0aadfc2, contains a null pointer dereference vulnerability in the Widevine pseudo-TA open_session handler that allows Normal World clients to cause a denial of service when CFG_WIDEVINE_PTA is enabled. Attackers can open a session directly on the Widevine PTA to trigger an unconditional dereference of a NULL calling session pointer via is_user_ta_ctx(), faulting the TEE at S-EL1 and crashing the trusted execution environment.

## Remediation

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