GPU memory corruption via unsupported user fences
Published Jul 19, 2026 · Updated Jul 19, 2026
Memory corruption in the AMDGPU JPEG v3.0 ring in Linux Kernel allows local users to corrupt GPU memory via a crafted command submission. The ring accepts AMDGPU_CHUNK_ID_FENCE even though JPEG v3.0 cannot perform 64-bit user-fence writes, causing GPCOM to write a sequence number to an attacker-influenced GPU virtual address. Access to an AMDGPU render node on affected VCN 3.0.x hardware is required; exploitation can disclose or corrupt GPU memory or hang GPU workloads until reset.
Summary
What happened
Memory corruption in the AMDGPU JPEG v3.0 ring in Linux Kernel allows local users to corrupt GPU memory via a crafted command submission. The ring accepts AMDGPU_CHUNK_ID_FENCE even though JPEG v3.0 cannot perform 64-bit user-fence writes, causing GPCOM to write a sequence number to an attacker-influenced GPU virtual address. Access to an AMDGPU render node on affected VCN 3.0.x hardware is required; exploitation can disclose or corrupt GPU memory or hang GPU workloads until reset.
The record
- CVE
- CVE-2026-63846
- Published
- Jul 19, 2026
- Updated
- Jul 19, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 19, 2026CVE publishedPublication date reported by the CVE source.
- Jul 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.9
- Affected versionversion=dfd57dbf44ddc70c90c76f83b2deb46e5dd40ce3 <303da8279f195cc741adc52c1b44d6b64de63bb0
- Affected versionversion=dfd57dbf44ddc70c90c76f83b2deb46e5dd40ce3 <48ce00787e3fddd2b45692fc991b8ab128343da5
- Affected versionversion=dfd57dbf44ddc70c90c76f83b2deb46e5dd40ce3 <5ada37d7f736f9feeaa06a25e470a4c74e67a61a
- Affected versionversion=dfd57dbf44ddc70c90c76f83b2deb46e5dd40ce3 <a2baf12eec41f246689e6a3f8619af1200031576
- Affected versionversion=dfd57dbf44ddc70c90c76f83b2deb46e5dd40ce3 <ee035a9d3eed3a9f5a3e83c31a10b321c9598861
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What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Technologies
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Your stack
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