SB2026072025 - Out-of-bounds read in Linux kernel iommu amd driver
Published: July 20, 2026
Security Bulletin ID
SB2026072025
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Out-of-bounds read (CVE-ID: CVE-2026-64186)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N]
The vulnerability allows a local user to perform an out-of-bounds memory access.
The vulnerability exists due to an out-of-bounds access in AMD IOMMU debugfs handlers when parsing user-supplied debugfs offset values. A local user can provide a sufficiently large value that becomes negative to perform an out-of-bounds memory access.
The issue affects the iommu_mmio_write() and iommu_capability_write() paths in the AMD IOMMU debugfs interface.
Remediation
Install update from vendor's website.