optee-os — security advisory

{
  "id": "4b073d753cd53fa7b7d0bf11415c883ee3b8f144c5c6b50c85517f854042f208",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-44362",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2026-44362",
    "summary": "OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 3.20.0 and prior to version 4.11.0, a vulnerability in OP-TEE’s subkey rollback protection allows the use of revoked or older subkey versions because the system fails to propagate versioning data during the Trusted Application (TA) loading process. In `core/crypto/signed_hdr.c`, the function `shdr_load_pub_key()` parses subkey headers but does not assign the `subkey_version` to the runtime `shdr_pub_key` structure. As a result, the `key->version` field remains at zero regardless of the version specified in the header. When `ree_fs_ta_open()` in `core/kernel/ree_fs_ta.c` calls `check_update_version()`, it passes this zeroed version to the rollback database. Because the database never receives a non-zero version to record, it never advances, effectively bypassing the rollback check and allowing TAs signed with downgraded subkey chains to load successfully. This impacts OP-TEE mainline configurations that utilize subkey-based signing chains for Trusted Application (TA) authentication. Version 4.11.0 contains a patch. No known workarounds are available.",
    "evidence": "osv:DEBIAN-CVE-2026-44362",
    "products": [
      {
        "name": {
          "value": "optee-os",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "4.10.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "4.10.0-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "4.5.0-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "4.7.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "4.8.0-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "4.9.0-1",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "DEBIAN-CVE-2026-44362",
      "aliases": [
        "DEBIAN-CVE-2026-44362"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "optee-os",
            "purl": "pkg:deb/debian/optee-os?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "versions": [
            "4.10.0-1",
            "4.10.0-2",
            "4.5.0-2",
            "4.7.0-1",
            "4.8.0-1",
            "4.9.0-1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44362.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-26T11:47:36.866053361Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-44362"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2026-44362"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-44362",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 450906,
  "published_at": "2026-07-06T20:16:33.95+00:00"
}