What is the CVSS score of CVE-2026-63854?

CVE-2026-63854 has a CVSS 3.1 base score of 7.8 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.2%.

How to fix or mitigate CVE-2026-63854?

Within 24 hours, query your asset inventory and Linux systems management tools to identify all servers and workstations running kernel 5.9 or later with AMD GPU hardware (VCN 3.0 support) and document affected systems by department and criticality. Within 7 days, apply the available vendor-released kernel patch from your Linux distribution provider to all identified systems, scheduling updates during maintenance windows and prioritizing production infrastructure. Within 30 days, verify deployment completion through automated system audits, re-scan to confirm patch application, and validate no systems remain unpatched or vulnerable.

Linux Kernel CVE-2026-63854

Q: Which versions of Linux Kernel are affected by CVE-2026-63854?

A local privilege escalation vulnerability in the AMD GPU driver (VCN 3.0) affects Linux systems running kernels 5.9 and later, allowing authenticated users with GPU access to corrupt kernel memory…. A patch is available.

EUVD-2026-45538 HIGH

Improper Input Validation (CWE-20)

2026-07-19 Linux

GHSA-3g9q-994v-2h99

Information Disclosure Linux

7.8

CVSS 3.1 · Vendor: Linux

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Obtain local render-node access
Delivery

Craft amdgpu CS with 64-bit user fence
Exploit

Target VCN 3.0 enc/dec ring
Execution

Trigger unsupported kernel fence write
Persist

Corrupt kernel memory
Impact

Escalate privileges or crash host

Vulnerability Assessment

Weakness	CWE CWE-20 OWASP Top 10:2025 A05:2025 - Injection ASVS 5.0 V2 - Validation and Business Logic Input validation, allowlisting
Exploitation Conditions	Exploitation requires local access to a system running a vulnerable Linux kernel with an AMD GPU that exposes VCN v3.0 encode/decode rings, and the attacker must be able to open the amdgpu DRI render node (/dev/dri/renderD*) and issue command-submission ioctls - i.e., PR:L authenticated local access, no user interaction (UI:N). The specific trigger is a CS submission that includes a 64-bit user fence directed at a VCN 3.0 enc/dec ring, which the hardware does not support. Limiting factors: it is local-only (not remotely exploitable), depends on the presence of AMD VCN 3.0 hardware, requires the attacker to already have render-node/GPU access (so hardened single-user or GPU-less servers are largely unaffected), and is neutralized on patched kernels that set no_user_fence to reject such submissions.
Impact	Signals are consistent and point to a real but locally-scoped issue rather than an internet-facing emergency. The CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, base 7.8) reflects that an attacker needs local access and low privileges (a user with access to the GPU render node) but can then achieve high confidentiality, integrity, and availability impact via kernel memory corruption. EPSS is low (0.16%, 5th percentile) and the CVE is NOT on CISA KEV, so there is no evidence of active exploitation and no public exploit code was identified. There is no SSVC decision data or POC provided. The kernel is ubiquitous, which raises aggregate exposure, but the local-only vector and the requirement of AMD VCN 3.0 hardware plus render-node access substantially narrow the realistic attack surface. Net: a legitimate patch-worthy kernel bug for multi-user or sandbox-escape threat models, but not a drop-everything remote threat.
Exploit ScenarioDerived	A logged-in local user (or code running inside a container or browser/GPU sandbox that has been granted access to the AMD render node) crafts an amdgpu command submission targeting a VCN 3.0 enc/dec ring and requests a 64-bit user fence write to an address the hardware mishandles, corrupting kernel memory to escalate privileges or crash the system. No public exploit is identified at time of analysis, and the local, low-complexity, low-privilege vector (AV:L/AC:L/PR:L) means a working exploit would require GPU/kernel-internals expertise but no user interaction.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

Patch available 0.2% exploitation probability (EPSS)

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AnalysisAIv1 – Jul 20, 2026

Local privilege escalation and memory-corruption risk in the amdgpu driver's VCN (Video Core Next) v3.0 encoder/decoder rings allows an authenticated local user with GPU render-node access to submit command streams containing 64-bit user-fence writes that the hardware does not support, corrupting kernel memory. The fix marks these rings with no_user_fence so the kernel rejects any command submission carrying a user fence. This affects Linux kernels from 5.9 onward that ship the AMD VCN 3.0 support; there is no public exploit identified at time of analysis and EPSS exploitation probability is low at 0.16% (5th percentile).

RemediationAI

Vendor-released patch: update to a fixed stable kernel - 6.6.141, 6.12.91, 6.18.33, 7.0.10, or 7.1 (or later) - matching your kernel series; the fixes are the stable cherry-picks of upstream commit 663bed3c7b8b (stable commits e74fc9c72c1b, 26c4f38529ac, 2d6525e7b250, b076e45e6f75, f1e5a6660d7c, referenced at https://git.kernel.org/stable/). Apply your distribution's kernel update and reboot; live patching is unlikely to cover a driver ring-flag change. If you cannot patch immediately, reduce exposure by restricting access to the AMD DRI render nodes (e.g., tighten permissions/group membership on /dev/dri/renderD* so only trusted users and services can submit GPU command streams), which limits who can reach the vulnerable CS path at the cost of breaking GPU acceleration for non-privileged users and containers; on servers that do not need AMD hardware video encode/decode you can also avoid loading/using the VCN paths. Consult vendor advisories at the kernel.org stable commits and the NVD/EUVD entries (EUVD-2026-45538) for series-specific fixed versions.

Affected VersionsENISA

Linux cf14826cdfb5c9fe10f98210d040b9d7486c381d <b076e45e6f757a2829e80d0144c1b5f201bee5af

Linux patch: 6.12.91

Linux patch: 7.0.10

Linux patch: 6.6.141

Linux patch: 0

Linux cf14826cdfb5c9fe10f98210d040b9d7486c381d <f1e5a6660d7cbf006079126d9babbf0ccf538c6b

Linux cf14826cdfb5c9fe10f98210d040b9d7486c381d <26c4f38529ac78930c9c4713e16ebc5b689bb0a3

Linux patch: 7.1

Linux 5.9

Linux cf14826cdfb5c9fe10f98210d040b9d7486c381d <e74fc9c72c1ba78d0de0b849f5929c3b39a8e20c

Linux patch: 6.18.33

Linux cf14826cdfb5c9fe10f98210d040b9d7486c381d <2d6525e7b2504f5bbfe9417cddc1e8da858791dd

Affected Packages

euvd linux no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The vulnerability lives in AMD's amdgpu kernel graphics driver, specifically the Video Core Next (VCN) v3.0 block that provides hardware video encode/decode. GPU work is submitted via command submission (CS) ioctls that reference GPU rings; 'user fences' are a mechanism where the GPU writes a completion value to a user-supplied memory address so userspace can track job completion. The VCN 3.0 enc/dec rings physically cannot perform 64-bit user-fence writes, yet the driver previously accepted CS submissions requesting them, leading to undefined/out-of-bounds fence writes. The remediation (cherry-picked from upstream commit 663bed3c7b8b) sets the no_user_fence ring flag so the CS path rejects such submissions. The CWE is not assigned by NVD, but the class is improper validation of a hardware capability leading to memory corruption (broadly CWE-787 out-of-bounds write / CWE-20 improper input validation). Affected products per CPE are cpe:2.3:a:linux:linux, i.e., the mainline Linux kernel.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (Linux) PRIMARY 7.8 HIGH

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

vuln.today AI 7.8 HIGH

Local attacker with render-node access (AV:L, PR:L) triggers kernel memory corruption with no user interaction, yielding high confidentiality, integrity, and availability impact.

3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

4.0 AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

SUSE 5.5 MEDIUM

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Primary rating from Vendor (Linux).

CVSS VectorVendor: Linux

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVSS changed

Jul 20, 2026 - 15:22 NVD

7.8 (HIGH)

Patch available

Jul 19, 2026 - 16:19 EUVD

CVE Published

Jul 19, 2026 - 14:04 cve.org

HIGH 7.8

CVE Published

Jul 19, 2026 - 14:04 cve.org

UNKNOWN (no severity yet)

DescriptionCVE.org

In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu/vcn: set no_user_fence for VCN v3.0 enc/dec rings

VCN encoder and decoder rings do not support 64-bit user fence writes, reject CS submissions with user fences.

(cherry picked from commit 663bed3c7b8b9a7624b0d95d300ddae034ad0614)

Executive ViewAI

Why It Matters

A local privilege escalation vulnerability in the AMD GPU driver (VCN 3.0) affects Linux systems running kernels 5.9 and later, allowing authenticated users with GPU access to corrupt kernel memory and escalate privileges. This impacts organizations operating AMD-based Linux workstations and servers; a successful exploit could result in complete system compromise. While exploitation probability remains low (0.2% EPSS) due to required local authentication and specific hardware configuration, the severity of kernel-level access warrants prompt remediation.

Business Impact: High

Compensating Controls

Apply vendor patch.

Threat Intelligence Overview

EPSS Score

0.2%

Top 95% exploitable

Prevalence

High

Linux kernel is ubiquitous but this bug needs AMD VCN 3.0 GPU hardware

Data Quality

6 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS Vendor

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC No

EPSS 0.2%

Patch available Yes

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

None

System Exposure· derived

Small

Automatable· derived

Human Impact

High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +39

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Same weakness CWE-20 – Improper Input Validation

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Same technique Information Disclosure

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CVE-2019-2725 CRITICAL POC

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CVE-2021-34523 CRITICAL POC

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CVE-2013-2251 CRITICAL POC

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CVE-2017-5638 CRITICAL POC

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CVE-2025-24813 CRITICAL POC

9.8

CVE-2025-68613 HIGH POC

8.8

CVE-2015-1701 HIGH POC

7.8

CVE-2017-0147 HIGH POC

7.5

Vendor StatusVendor

SUSE

Severity: Moderate

Product	Status
SUSE Linux Enterprise Desktop 15 SP7	Not-Affected
SUSE Linux Enterprise Desktop 15 SP7	Not-Affected
SUSE Linux Enterprise High Availability Extension 15 SP7	Not-Affected
SUSE Linux Enterprise High Availability Extension 15 SP7	Not-Affected
SUSE Linux Enterprise High Availability Extension 16.0	Not-Affected

References

Advisories & patches

ADVISORY https://nvd.nist.gov/vuln/detail/CVE-2026-63854 ADVISORY https://seclists.org/oss-sec/2026/q3/230 ADVISORY https://ubuntu.com/security/notices/USN-8574-1 ADVISORY https://vuldb.com/vuln/380171 REF https://git.kernel.org/stable/c/26c4f38529ac78930c9c4713e16ebc5b689bb0a3 REF https://git.kernel.org/stable/c/2d6525e7b2504f5bbfe9417cddc1e8da858791dd REF https://git.kernel.org/stable/c/b076e45e6f757a2829e80d0144c1b5f201bee5af REF https://git.kernel.org/stable/c/e3d339b0d9051d49eb9c78459091bba4fb525100 REF https://git.kernel.org/stable/c/e74fc9c72c1ba78d0de0b849f5929c3b39a8e20c REF https://git.kernel.org/stable/c/f1e5a6660d7cbf006079126d9babbf0ccf538c6b

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