Files
vuln-cve/data/2026/121xxx/CVE-2026-121876.json
T

227 lines
11 KiB
JSON

{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-121876",
"assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"state": "PUBLISHED",
"assignerShortName": "redhat",
"dateReserved": "2026-11-04T10:34:49.034Z",
"datePublished": "2026-11-12T16:55:35.424Z",
"dateUpdated": "2026-11-12T18:49:52.690Z"
},
"containers": {
"cna": {
"title": "Sandboxed-containers: kernel: systemd-gpt-auto-generator: guest data leakage in confidential computing (sandboxed containers)",
"metrics": [
{
"other": {
"content": {
"value": "Important",
"namespace": "https://access.redhat.com/security/updates/classification/"
},
"type": "Red Hat severity rating"
}
},
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "NONE",
"baseScore": 7.9,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "HIGH",
"scope": "CHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N",
"version": "3.1"
},
"format": "CVSS"
}
],
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in the interaction between systemd-gpt-auto-generator and \nconfidential computing guest VM images in OpenShift Sandboxed Containers \n(confidential peer pods). systemd-gpt-auto-generator automatically discovers \nand mounts GPT partitions by type GUID at boot with no user confirmation. In \nthe confidential computing threat model, where the host/hypervisor is the \nadversary, a malicious host can inject partitions into the guest's virtual \ndisk. Most critically, injecting a swap partition causes the guest kernel to \npage out TEE-encrypted memory to a host-controlled block device, breaking the \nconfidentiality guarantee of the hardware TEE (AMD SEV-SNP, Intel TDX).\n\nThe PodVM images use a GPT-partitioned disk with dm-verity on the root \npartition. However, the roothash= kernel parameter only disables root \nauto-discovery — non-root partitions (swap, /home, /var, /srv, /var/tmp) are \nstill auto-discovered and mounted. The generator is shipped unmasked in the \nRHEL systemd-udev subpackage, and no kernel command line parameter in the \nmeasured UKI addon disables it. Additionally, the PodVM measurement script \ncaptures PCRs 3, 9, 11, and 12, but not PCR 5 (GPT partition table), so \npartition table modifications are not detected by remote attestation."
}
],
"affected": [
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 10",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "kernel",
"defaultStatus": "affected",
"cpes": [
"cpe:/a:redhat:enterprise_linux:10"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 6",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "kernel",
"defaultStatus": "affected",
"cpes": [
"cpe:/o:redhat:rhel_els:6"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 7",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "kernel",
"defaultStatus": "affected",
"cpes": [
"cpe:/o:redhat:rhel_els:7"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 7",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "kernel-rt",
"defaultStatus": "affected",
"cpes": [
"cpe:/o:redhat:rhel_els:7"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 8",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "kernel",
"defaultStatus": "affected",
"cpes": [
"cpe:/a:redhat:enterprise_linux:8"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 8",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "kernel-rt",
"defaultStatus": "affected",
"cpes": [
"cpe:/a:redhat:enterprise_linux:8"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 9",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "kernel",
"defaultStatus": "affected",
"cpes": [
"cpe:/a:redhat:enterprise_linux:9"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 9",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "kernel-rt",
"defaultStatus": "affected",
"cpes": [
"cpe:/a:redhat:enterprise_linux:9"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat OpenShift Container Platform 4",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "openshift/ose-rhel-coreos-8",
"defaultStatus": "affected",
"cpes": [
"cpe:/a:redhat:openshift:4"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat OpenShift Container Platform 4",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "openshift/ose-rhel-coreos-9",
"defaultStatus": "affected",
"cpes": [
"cpe:/a:redhat:openshift:4"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat OpenShift Container Platform 5",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "openshift/ose-rhel-coreos-9",
"defaultStatus": "affected",
"cpes": [
"cpe:/a:redhat:openshift:5"
]
}
],
"references": [
{
"url": "https://access.redhat.com/security/cve/CVE-2026-121876",
"tags": [
"vdb-entry",
"x_refsource_REDHAT"
]
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2558210",
"name": "RHBZ#2558210",
"tags": [
"issue-tracking",
"x_refsource_REDHAT"
]
}
],
"datePublic": "2026-11-12T14:00:00.000Z",
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-359",
"description": "Exposure of Private Personal Information to an Unauthorized Actor",
"lang": "en",
"type": "CWE"
}
]
}
],
"x_redhatCweChain": "CWE-359: Exposure of Private Personal Information to an Unauthorized Actor",
"workarounds": [
{
"lang": "en",
"value": "Add systemd.gpt_auto=0 to the measured kernel command line (UKI addon) to completely \ndisable systemd-gpt-auto-generator. Since the PodVM already uses explicit partition \nlayout and dm-verity, auto-discovery is unnecessary.\n\nThe patches released are using the following mitigation: `systemd.image_policy=root=open`.\n\nAlternative mitigations:\n- Disable swap specifically: add systemd.swap=0 to the kernel command line\n- Mask the generator in the guest image: \n ln -sf /dev/null /etc/systemd/system-generators/systemd-gpt-auto-generator\n- Include PCR 5 in the PodVM measurement script alongside PCRs 3, 9, 11, 12\n- For systemd 254+: set restrictive image policy via systemd.image_policy=root=verity+signed+encrypted+unprotected+absent:swap=absent:home=absent:srv=absent:var=absent:tmp=absent"
}
],
"timeline": [
{
"lang": "en",
"time": "2026-10-16T00:00:00.000Z",
"value": "Reported to Red Hat."
},
{
"lang": "en",
"time": "2026-11-12T14:00:00.000Z",
"value": "Made public."
}
],
"credits": [
{
"lang": "en",
"value": "Red Hat would like to thank Spyros Seimenis (Edgeless Systems) for reporting this issue."
}
],
"providerMetadata": {
"orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
"shortName": "redhat",
"dateUpdated": "2026-11-12T18:49:52.690Z"
},
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
}
}