{"affected":[{"defaultStatus":"affected","ecosystem":"github","packageName":"OP-TEE/optee_os","product":"optee_os","source":"CNA: VulnCheck","vendor":"OP-TEE","versions":[{"lessThanOrEqual":"4.10.0","status":"affected","version":"0","versionType":"semver"},{"status":"unaffected","version":"0aadfc23407f50e770eb5ddd871fc208f5626833","versionType":"git"}]}],"cveId":"CVE-2026-71967","cwes":["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.","epss":{"date":"2026-11-08","percentile":0.06393,"score":0.0017},"exploits":[],"kev":null,"metrics":[{"score":5.7,"severity":"medium","source":"CNA: VulnCheck","vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},{"score":5.5,"severity":"medium","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}],"modifiedAt":1794146915738,"publishedAt":1786385461124,"references":[{"source":"CNA: VulnCheck","tags":["issue-tracking","patch"],"url":"https://github.com/OP-TEE/optee_os/pull/7899"},{"source":"CNA: VulnCheck","tags":["patch"],"url":"https://github.com/OP-TEE/optee_os/commit/0aadfc23407f50e770eb5ddd871fc208f5626833"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/op-tee-os-null-pointer-dereference-dos-via-widevine-pta-open-session"}],"remediation":[{"kind":"fix","source":"CNA: VulnCheck","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/OP-TEE/optee_os/pull/7899"},{"kind":"fix","source":"CNA: VulnCheck","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/OP-TEE/optee_os/commit/0aadfc23407f50e770eb5ddd871fc208f5626833"}],"revision":"99d8754679c2bb8fa55bc2af8a125b3adf3b8dee7f72a6050ac42e97ff1c3de4","sources":[{"modifiedAt":1794146915738,"name":"CNA: VulnCheck","retrievedAt":1794151327756,"url":"https://www.cve.org/CVERecord?id=CVE-2026-71967"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1794151337824,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-71967"}],"ssvc":{"assessedAt":1786388312879,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"OP-TEE OS 4.10.0 NULL Pointer Dereference DoS via Widevine PTA open_session","updatedAt":1794151337824}