Local privilege escalation via undersized queue allocation
Published Jul 19, 2026 · Updated Jul 19, 2026
Integer overflow in the KFD debugger in Linux Kernel allows local users to corrupt kernel heap memory through a crafted ioctl. get_queue_ids() multiplies attacker-controlled num_queues by four in 32-bit size_t before memdup_user(), so wraparound creates a buffer smaller than subsequent queue reads and writes require. Access to /dev/kfd, a KFD debug-trap session, and a 32-bit size_t kernel build are required; exploitation can disclose or modify kernel memory, panic the kernel, or elevate privileges.
Summary
What happened
Integer overflow in the KFD debugger in Linux Kernel allows local users to corrupt kernel heap memory through a crafted ioctl. get_queue_ids() multiplies attacker-controlled num_queues by four in 32-bit size_t before memdup_user(), so wraparound creates a buffer smaller than subsequent queue reads and writes require. Access to /dev/kfd, a KFD debug-trap session, and a 32-bit size_t kernel build are required; exploitation can disclose or modify kernel memory, panic the kernel, or elevate privileges.
The record
- CVE
- CVE-2026-63881
- 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
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <6.12.93
- Affected versionversion=0 <6.18.35
- Affected versionversion=0 <6.6.143
- Affected versionversion=0 <7.0.12
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4e5f808b454167cc58d7084a407a554d8ddc694d
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4f9eeedc3d3151f8a226fd676c314a813edda5a1
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5cf4a41aa0d74e4c83f82d2ce233b5189ed4b43c
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <93f5534b35a05ef8a0109c1eefa800062fee810a
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <de70a80992396ee306ee3a2810ad28aa1608ba9b
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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