optee-os — security advisory
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
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"
}