{"id":"UBUNTU-CVE-2026-71967","details":"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.","modified":"2026-08-13T03:01:05.318905150Z","published":"2026-08-10T19:17:00Z","upstream":["CVE-2026-71967"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-71967"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-71967"},{"type":"REPORT","url":"https://github.com/OP-TEE/optee_os/commit/0aadfc23407f50e770eb5ddd871fc208f5626833"},{"type":"REPORT","url":"https://github.com/OP-TEE/optee_os/pull/7899"},{"type":"REPORT","url":"https://www.vulncheck.com/advisories/op-tee-os-null-pointer-dereference-dos-via-widevine-pta-open-session"}],"affected":[{"package":{"name":"optee-os","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/optee-os?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.7.0-1","4.8.0-1"],"ecosystem_specific":{"binaries":[{"binary_version":"4.8.0-1","binary_name":"optee-os"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71967.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V4","score":"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"},{"type":"Ubuntu","score":"medium"}]}