Local privilege escalation via unsupported fence writes
Published Jul 19, 2026 · Updated Jul 19, 2026
Memory corruption in Linux kernel AMDGPU JPEG v4.0.5 rings allows local users to escalate privileges via crafted submissions. The ring initializer leaves no_user_fence unset, so DRM_IOCTL_AMDGPU_CS accepts a 64-bit user-fence write that the JPEG engine does not support. Exploitation requires local access to an AMDGPU render node on VCN 4.0.5 hardware and provides GPU-driven writes to attacker-chosen GPU virtual addresses, enabling kernel code execution or disclosure and potentially causing GPU hangs or resets.
Summary
What happened
Memory corruption in Linux kernel AMDGPU JPEG v4.0.5 rings allows local users to escalate privileges via crafted submissions. The ring initializer leaves no_user_fence unset, so DRM_IOCTL_AMDGPU_CS accepts a 64-bit user-fence write that the JPEG engine does not support. Exploitation requires local access to an AMDGPU render node on VCN 4.0.5 hardware and provides GPU-driven writes to attacker-chosen GPU virtual addresses, enabling kernel code execution or disclosure and potentially causing GPU hangs or resets.
The record
- CVE
- CVE-2026-63843
- Published
- Jul 19, 2026
- Updated
- Jul 19, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1068
- 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
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.7
- Affected versionversion=8f98a715da8e906cff5c635f9eb5399b84751557 <424510b60d4698a75a6ff71acdd88b528f0f39af
- Affected versionversion=8f98a715da8e906cff5c635f9eb5399b84751557 <b65b7f3f3c18f797f81a2af7c97e2079900ad6db
- Affected versionversion=8f98a715da8e906cff5c635f9eb5399b84751557 <f26e3f7186cd6ecc93e6af102744d64c798dea7e
- Affected versionversion=8f98a715da8e906cff5c635f9eb5399b84751557 <f9bc5633b761cff200c428f61ed0df6212b1c721
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo