Linux Kernel up to 6.18.6 IOMMU Interface vfree privilege escalation

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.18.6. It has been rated as critical. This impacts the function vfree of the component IOMMU Interface. This manipulation causes an unknown weakness. This vulnerability appears as CVE-2025-71202. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.6. It has been declared as critical. Affected by this vulnerability is the function vfree of the component IOMMU Interface. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: iommu/sva: invalidate stale IOTLB entries for kernel address space Introduce a new IOMMU interface to flush IOTLB paging cache entries for the CPU kernel address space. This interface is invoked from the x86 architecture code that manages combined user and kernel page tables, specifically before any kernel page table page is freed and reused. This addresses the main issue with vfree() which is a common occurrence and can be triggered by unprivileged users. While this resolves the primary problem, it doesn't address some extremely rare case related to memory unplug of memory that was present as reserved memory at boot, which cannot be triggered by unprivileged users. The discussion can be found at the link below. Enable SVA on x86 architecture since the IOMMU can now receive notification to flush the paging cache before freeing the CPU kernel page table pages.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2025-71202 since 01/31/2026. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/06/2026).

The vulnerability scanner Nessus provides a plugin with the ID 299070 (Linux Distros Unpatched Vulnerability : CVE-2025-71202), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.7 eliminates this vulnerability. Applying the patch 9f0a7ab700f8620e433b05c57fbd26c92ea186d9/e37d5a2d60a338c5917c45296bac65da1382eda5 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (299070) and CERT Bund (WID-SEC-2026-0421). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Google Container-Optimized OS
• Debian Linux
• Google Cloud Platform
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel
• IBM QRadar SIEM

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6

License

• open-source

Website

• Vendor: https://www.kernel.org/

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