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optee-os — security advisory

Type: advisorySources: OSVAdvisory ID: UBUNTU-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.

Products
optee-os
Affected versions
4.10.0-1, 4.10.0-2, 4.7.0-1, 4.8.0-1
Fixed versions
Not specified
CVEs
CVE-2026-71967
Confirmed fixed CVEs
Not specified
Updated in this feed
31 Oct 2026, 03:15 UTC · Revision 1

Source evidence

UBUNTU-CVE-2026-71967

core-osv · Original source

Published 10 Aug 2026, 19:17 UTC

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.

osv:UBUNTU-CVE-2026-71967

optee-os

Fixed versions: Not specified

optee-os

Fixed versions: Not specified

Complete source record
{
  "id": "090c6e85a9d13127f7ea9833cbc2b58e739f05f579a4490d7c71bd6268278242",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-71967",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-71967",
    "summary": "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.",
    "evidence": "osv:UBUNTU-CVE-2026-71967",
    "products": [
      {
        "name": {
          "value": "optee-os",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "4.8.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "4.10.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "4.10.0-2",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "optee-os",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "4.7.0-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "4.8.0-1",
            "evidence": "/affected/1/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "UBUNTU-CVE-2026-71967",
      "aliases": [
        "UBUNTU-CVE-2026-71967"
      ],
      "metrics": [
        {
          "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"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "optee-os",
            "purl": "pkg:deb/ubuntu/optee-os?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "4.8.0-1",
            "4.10.0-1",
            "4.10.0-2"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71967.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "optee-os",
                "binary_version": "4.10.0-2"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "optee-os",
            "purl": "pkg:deb/ubuntu/optee-os?arch=source&distro=resolute",
            "ecosystem": "Ubuntu:26.04:LTS"
          },
          "versions": [
            "4.7.0-1",
            "4.8.0-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71967.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "optee-os",
                "binary_version": "4.8.0-1"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T13:00:48.257218082Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-71967"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-71967",
        "https://www.cve.org/CVERecord?id=CVE-2026-71967",
        "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"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-71967",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/1/score"
  },
  "source_id": "core-osv",
  "document_id": 360848,
  "published_at": "2026-08-10T19:17:00+00:00"
}