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The vulnerability, CVE-2025-71202, resides in the Linux kernel’s IOMMU (Input-Output Memory Management Unit) Shared Virtual Addressing (SVA) subsystem on x86 architecture . The core issue is a missing invalidation of the IOTLB (Input/Output Translation Lookaside Buffer), a hardware cache that stores address translations for I/O devices . When the kernel frees and reuses pages from its page tables—a common operation triggered by unprivileged users via functions like vfree()—the IOMMU is not notified . Consequently, it retains stale I/O address mappings (IOTLB entries) that point to memory locations that may have been reallocated . This creates a use-after-free condition where a DMA (Direct Memory Access) operation could access the wrong physical memory, leading to memory corruption, system instability, or potential privilege escalation . The fix introduces a new IOMMU interface to flush these stale entries specifically for the kernel address space before any kernel page table page is freed, thereby synchronizing the CPU and IOMMU views of memory .
dailycve form:
Platform: Linux Kernel
Version: v6.18 affected
Vulnerability : Privilege Escalation
Severity: High
date: 02/14/2026
Prediction: Patched in v6.18.8
What Undercode Say:
Analytics:
The vulnerability is triggered locally by an unprivileged user, primarily through common `vfree()` operations which are part of normal system behavior . The attack vector involves forcing the kernel to free and reuse page table pages while I/O operations are ongoing, exploiting the window where stale IOTLB entries exist . While the root cause is a use-after-free (CWE-416) in the IOMMU/SVA component, exploitation is considered complex due to the need for precise memory layout control and simultaneous I/O . The impact is high, as successful exploitation could lead to system crash (denial of service) or arbitrary code execution with kernel privileges . Systems with x86 architecture and SVA (Shared Virtual Addressing) enabled are the primary targets . The vulnerability is present in multiple Debian versions (stretch, buster, bullseye, bookworm) and SUSE Linux Enterprise products, though some older versions are marked as not affected .
Bash Commands and Code:
Check if your kernel is vulnerable (example for Debian-based systems) A kernel version lower than 6.18.8-1 is likely vulnerable uname -r Check if SVA (Shared Virtual Addressing) is enabled on your system dmesg | grep -i "sva|iommu" As a temporary workaround, disable IOMMU passthrough to limit exposure Edit the GRUB configuration file sudo nano /etc/default/grub Add the following parameter to the GRUB_CMDLINE_LINUX line: iommu.passthrough=1 Save the file and update GRUB, then reboot sudo update-grub sudo reboot
Exploit:
No public exploit is available at this time . Exploitation would require a local user to trigger a use-after-free condition in the kernel’s page table management, specifically around `vfree()` calls, and then leverage the stale IOTLB entry to corrupt memory or redirect I/O .
Protection from this CVE:
The primary protection is to apply the official kernel patch that introduces the IOTLB invalidation interface . This involves updating the Linux kernel to a fixed version, such as 6.18.8-1 or later for Debian, or pulling the commits `e37d5a2d60a3` and `9f0a7ab700f8` from the kernel git repository . As a temporary measure, administrators can disable SVA support by adding kernel boot parameters like `iommu.passthrough=1` if the system’s workload does not require this feature .
Impact:
Successful exploitation can lead to memory corruption, system instability, or a full system crash (denial of service) . In more severe scenarios, it could allow a local unprivileged user to escalate their privileges to root or kernel level, enabling them to bypass security mechanisms and gain complete control over the system . The confidentiality and integrity of the system could be compromised, as an attacker might read sensitive kernel memory or modify system behavior .
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Sources:
Reported By: nvd.nist.gov
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