CVE-2026-71967

MEDIUM 5.5

OP-TEE OS 4.10.0 NULL Pointer Dereference DoS via Widevine PTA open_session

CVSS Score

5.5

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-476
Vendor	op-tee
Product	optee_os
Published	Aug 10, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected Versions

OP-TEE / optee_os

0 ≤ 4.10.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/OP-TEE/optee_os/pull/7899 github.com: https://github.com/OP-TEE/optee_os/commit/0aadfc23407f50e770eb5ddd871fc208f5626833 vulncheck.com: https://www.vulncheck.com/advisories/op-tee-os-null-pointer-dereference-dos-via-widevine-pta-open-session

Credits

Argus Systems - ByteRay Ltd.