MMIO data disclosure via undersized boundary check
Published Jan 5, 2026 · Updated Jan 5, 2026
Out-of-bounds read in the AMD IOMMU debugfs handler in Linux Kernel 6.17 through 6.18.1 allows local users to disclose MMIO data. iommu_mmio_write accepts an offset validated for four bytes, while iommu_mmio_show passes that offset to readq for an eight-byte read. The mmio debugfs file is mode 0644, so setting the crafted offset requires root-equivalent access; the overread extends four bytes past mapped MMIO.
Summary
What happened
Out-of-bounds read in the AMD IOMMU debugfs handler in Linux Kernel 6.17 through 6.18.1 allows local users to disclose MMIO data. iommu_mmio_write accepts an offset validated for four bytes, while iommu_mmio_show passes that offset to readq for an eight-byte read. The mmio debugfs file is mode 0644, so setting the crafted offset requires root-equivalent access; the overread extends four bytes past mapped MMIO.
The record
- CVE
- CVE-2025-68760
- Published
- Jan 5, 2026
- Updated
- Jan 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Jan 5, 2026CVE publishedPublication date reported by the CVE source.
- Jan 5, 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=6.17
- Affected versionversion=7a4ee419e8c144b747a8915856e91a034d7c8f34 <0ec4aaf5f3f559716a6559f3d6d9616e9470bed6
- Affected versionversion=7a4ee419e8c144b747a8915856e91a034d7c8f34 <a0c7005333f9a968abb058b1d77bbcd7fb7fd1e7
- Affected versionversion=7a4ee419e8c144b747a8915856e91a034d7c8f34 <b959df804c33913dbfdb90750f2d693502b3d126
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
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Public exploit references
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Technologies
Your stack
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Your stack
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