{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-63853",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-07-19T07:54:57.016Z",
        "datePublished": "2026-07-19T14:04:43.885Z",
        "dateUpdated": "2026-08-05T12:36:31.693Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:36:31.693Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu/vcn: set no_user_fence for VCN v4.0 enc ring\n\nVCN encoder and decoder rings do not support 64-bit user fence writes,\nreject CS submissions with user fences.\n\n(cherry picked from commit fd852c048b46f9825e904a4f3f4538fe9d8827d9)"
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - Exploitation requires submitting a crafted AMDGPU command stream through DRM_IOCTL_AMDGPU_CS on a local /dev/dri/renderD* device; there is no network, adjacent-radio, or physical-access path to the vulnerable VCN v4.0 unified encoder ring handling.\nAC:L - An attacker with render-node access can deterministically submit a CS containing an AMDGPU_CHUNK_ID_FENCE chunk targeting the VCN encoder ring; no race, special timing, or victim state beyond having a VCN 4.0-capable AMDGPU is required.\nPR:L - The path is reachable by any local user who can open the DRM render node (typically membership in the render/video group on desktops, workstations, and cloud GPU VMs); it does not require real root in the init namespace.\nUI:N - Triggering the bug is fully programmatic via ioctl-based CS submission and does not require any victim to open files, mount filesystems, or perform other interactive actions.\nS:U - Impact is confined to the AMDGPU/VCN driver and GPU resources of the submitting security context; it does not cross a VM, container, or IOMMU security boundary to affect a different authority.\nC:H - Without the no_user_fence guard, amdgpu_ib_commit emits a 64-bit user fence (AMDGPU_FENCE_FLAG_64BIT) on a ring whose emit_fence path only supports 32-bit fence writes, causing the VCN hardware to perform an unvalidated GPU DMA write that can corrupt adjacent GPU-mapped memory and be leveraged for information disclosure.\nI:H - The same rogue GPU-initiated fence write is a memory-corruption primitive that can modify GPU-accessible buffers (including shared dma-buf mappings) outside the intended 8-byte fence field, enabling integrity violations and potential further exploitation.\nA:H - Malformed fence/trap commands on the VCN unified encoder ring can hang or fault the VCN block and force GPU/driver reset, denying graphics and compute availability to all users of the device on shared workstations and servers."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c"
                    ],
                    "versions": [
                        {
                            "version": "8da1170a16e4d4b49fa07d1f75ad480847ff7eca",
                            "lessThan": "1286b6872de0aee1feeeaa6dbac86369806de9a5",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8da1170a16e4d4b49fa07d1f75ad480847ff7eca",
                            "lessThan": "6bdd2ed6458d35c368fbe9550a4d7f342abd3a92",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8da1170a16e4d4b49fa07d1f75ad480847ff7eca",
                            "lessThan": "51f694221047c84fa185be98210eb2c354ffb8c6",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c"
                    ],
                    "versions": [
                        {
                            "version": "5.19",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.19",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.33",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.10",
                            "lessThanOrEqual": "7.0.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
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                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                                    "versionEndExcluding": "6.18.33"
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.19",
                                    "versionEndExcluding": "7.0.10"
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/1286b6872de0aee1feeeaa6dbac86369806de9a5"
                },
                {
                    "url": "https://git.kernel.org/stable/c/6bdd2ed6458d35c368fbe9550a4d7f342abd3a92"
                },
                {
                    "url": "https://git.kernel.org/stable/c/51f694221047c84fa185be98210eb2c354ffb8c6"
                }
            ],
            "title": "drm/amdgpu/vcn: set no_user_fence for VCN v4.0 enc ring",
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