NULL pointer dereference in Op-Tee Optee OS
CVE-2026-71967
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.002 (5.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 5.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001
Affected products
- Op-Tee Optee OS — versions 0, 0aadfc23407f50e770eb5ddd871fc208f5626833
Weakness classification (CWE)
References
- github.com/OP-TEE/optee_os/pull/7899 (issue-tracking)
- github.com/OP-TEE/optee_os/commit/0aadfc23407f50e770eb5ddd871fc208f5626833 (patch)
- www.vulncheck.com/advisories/op-tee-os-null-pointer-dereference-dos-via-widevin… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-71967?
- CVE-2026-71967 is a medium-severity vulnerability in Op-Tee Optee OS, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2026-08-10.
- How severe is CVE-2026-71967?
- Medium severity. CVSS v3 base score is 5.5 out of 10.