CVE-2026-71967: OP-TEE OS 4.10.0 NULL Pointer Dereference DoS via Widevine PTA open_session

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-10 · updated 2026-10-24
Weakness: CWE-476

Description

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.

Affected products

OP-TEE optee_os: through 4.10.0

References

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

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