CVE-2026-63851 (GCVE-0-2026-63851)
Vulnerability from cvelistv5 – Published: 2026-07-19 14:04 – Updated: 2026-08-05 12:36
VLAI
EPSS
VEX
Title
drm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 enc ring
Summary
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 enc ring
VCN encoder and decoder rings do not support 64-bit user fence writes,
reject CS submissions with user fences.
(cherry picked from commit 084d94ac93707bdda07efb5cee786f632de4219b)
Severity
7.8 (High)
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
547aad32edac17a3ec4989d8aad2426d0cbeb590 , < 75091030f07b7957cc0646cd52e2d9d15f611483
(git)
Affected: 547aad32edac17a3ec4989d8aad2426d0cbeb590 , < 6d9a98c5ed65ba92a09e4ca5a5f6941448145529 (git) Affected: 547aad32edac17a3ec4989d8aad2426d0cbeb590 , < 7f23b5c420b9f68a210c29c5123bace670aa8cc9 (git) Affected: 547aad32edac17a3ec4989d8aad2426d0cbeb590 , < 589a254bf3e88204c8402b9cbccd5e23a0af990f (git) |
guessed | |
| Linux | Linux |
Affected:
6.7
Unaffected: 0 , < 6.7 (semver) Unaffected: 6.12.91 , ≤ 6.12.* (semver) Unaffected: 6.18.33 , ≤ 6.18.* (semver) Unaffected: 7.0.10 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "75091030f07b7957cc0646cd52e2d9d15f611483",
"status": "affected",
"version": "547aad32edac17a3ec4989d8aad2426d0cbeb590",
"versionType": "git"
},
{
"lessThan": "6d9a98c5ed65ba92a09e4ca5a5f6941448145529",
"status": "affected",
"version": "547aad32edac17a3ec4989d8aad2426d0cbeb590",
"versionType": "git"
},
{
"lessThan": "7f23b5c420b9f68a210c29c5123bace670aa8cc9",
"status": "affected",
"version": "547aad32edac17a3ec4989d8aad2426d0cbeb590",
"versionType": "git"
},
{
"lessThan": "589a254bf3e88204c8402b9cbccd5e23a0af990f",
"status": "affected",
"version": "547aad32edac17a3ec4989d8aad2426d0cbeb590",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.7"
},
{
"lessThan": "6.7",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.91",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.33",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.10",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.91",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.33",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.0.10",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1",
"versionStartIncluding": "6.7",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 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 084d94ac93707bdda07efb5cee786f632de4219b)"
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - Exploitation requires submitting AMDGPU command streams via the DRM render node (DRM_IOCTL_AMDGPU_CS), which is a local ioctl/device-file interface with no network-facing entry point.\nAC:L - An attacker with render-node access can deterministically craft a CS submission with a FENCE chunk targeting the VCN_ENC ring; no race conditions or attacker-uncontrollable timing are required.\nPR:L - The only gate is access to /dev/dri/renderD* (DRM_AUTH|DRM_RENDER_ALLOW), which is available to unprivileged local users in the render/video group and does not require root or capabilities obtainable only in the init namespace.\nUI:N - Once the attacker has render-node access, triggering the bug requires no additional victim interaction beyond normal GPU command submission.\nS:U - Impact is confined to the same local security domain (kernel/GPU driver); exploitation does not cross a VM, container, or IOMMU security boundary to a different authority.\nC:H - The unsupported GPU fence operation causes the VCN hardware to perform DMA writes outside the driver\u0027s validated semantics, creating a memory-corruption primitive that could expose or corrupt GPU-mapped memory beyond the intended 8-byte fence slot.\nI:H - The bug enables GPU-initiated writes to attacker-chosen GPU virtual addresses (user fence buffer), and hardware misbehavior on unsupported fence commands can corrupt adjacent or shared dma-buf memory with unpredictable write patterns.\nA:H - Submitting unsupported user fences to the VCN ring can hang the GPU, trigger VCN poison/RAS interrupts, or crash the graphics subsystem, causing denial of service on affected systems."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T12:36:29.527Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/75091030f07b7957cc0646cd52e2d9d15f611483"
},
{
"url": "https://git.kernel.org/stable/c/6d9a98c5ed65ba92a09e4ca5a5f6941448145529"
},
{
"url": "https://git.kernel.org/stable/c/7f23b5c420b9f68a210c29c5123bace670aa8cc9"
},
{
"url": "https://git.kernel.org/stable/c/589a254bf3e88204c8402b9cbccd5e23a0af990f"
}
],
"title": "drm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 enc ring",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-63851",
"datePublished": "2026-07-19T14:04:42.581Z",
"dateReserved": "2026-07-19T07:54:57.016Z",
"dateUpdated": "2026-08-05T12:36:29.527Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-63851",
"date": "2026-10-01",
"epss": "0.00175",
"percentile": "0.0627"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "75091030f07b7957cc0646cd52e2d9d15f611483",
"status": "affected",
"version": "547aad32edac17a3ec4989d8aad2426d0cbeb590",
"versionType": "git"
},
{
"lessThan": "6d9a98c5ed65ba92a09e4ca5a5f6941448145529",
"status": "affected",
"version": "547aad32edac17a3ec4989d8aad2426d0cbeb590",
"versionType": "git"
},
{
"lessThan": "7f23b5c420b9f68a210c29c5123bace670aa8cc9",
"status": "affected",
"version": "547aad32edac17a3ec4989d8aad2426d0cbeb590",
"versionType": "git"
},
{
"lessThan": "589a254bf3e88204c8402b9cbccd5e23a0af990f",
"status": "affected",
"version": "547aad32edac17a3ec4989d8aad2426d0cbeb590",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.7"
},
{
"lessThan": "6.7",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.91",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.33",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.10",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 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 084d94ac93707bdda07efb5cee786f632de4219b)"
}
],
"id": "CVE-2026-63851",
"lastModified": "2026-07-27T17:44:23.777",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-07-19T15:16:51.907",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/589a254bf3e88204c8402b9cbccd5e23a0af990f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/6d9a98c5ed65ba92a09e4ca5a5f6941448145529"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/75091030f07b7957cc0646cd52e2d9d15f611483"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7f23b5c420b9f68a210c29c5123bace670aa8cc9"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
},
"redhat_vex": {
"aggregate_severity": "Low",
"current_release_date": "2026-08-05T14:05:47+00:00",
"cve": "CVE-2026-63851",
"id": "CVE-2026-63851",
"initial_release_date": "2026-07-19T00:00:00+00:00",
"product_status:known_affected": "198",
"product_status:known_not_affected": "76",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: drm/amdgpu/vcn: set no_user_fence for VCN v4.0.5 enc ring",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63851.json",
"version": "3"
},
"suse_vex": {
"aggregate_severity": "moderate",
"current_release_date": "2026-10-01T00:50:00Z",
"cve": "CVE-2026-63851",
"id": "CVE-2026-63851",
"initial_release_date": "2026-07-24T02:13:40Z",
"product_status:known_affected": "484",
"product_status:known_not_affected": "229",
"product_status:recommended": "250",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2026-63851",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-63851.json",
"version": "10"
}
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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