Linux Kernel up to 6.6.117/6.12.59/6.17.9 buffer overflow

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 6.6.117/6.12.59/6.17.9. The affected element is an unknown function. Performing a manipulation results in buffer overflow. This vulnerability is cataloged as CVE-2025-40266. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.117/6.12.59/6.17.9. It has been classified as critical. This affects some unknown functionality. The manipulation with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Check the untrusted offset in FF-A memory share Verify the offset to prevent OOB access in the hypervisor FF-A buffer in case an untrusted large enough value [U32_MAX - sizeof(struct ffa_composite_mem_region) + 1, U32_MAX] is set from the host kernel.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-40266 since 04/16/2025. The exploitability is told to be easy. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/04/2026).

The vulnerability scanner Nessus provides a plugin with the ID 277509 (Linux Distros Unpatched Vulnerability : CVE-2025-40266), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.118, 6.12.60 or 6.17.10 eliminates this vulnerability. Applying the patch fc3139d9f4c1fe1c7d5f25f99676bd8e9c6a1041/bc1909ef38788f2ee3d8011d70bf029948433051/f9f1aed6c8a3427900da3121e1868124854569c3/103e17aac09cdd358133f9e00998b75d6c1f1518 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 (277509), EUVD (EUVD-2025-201191) and CERT Bund (WID-SEC-2025-2747). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Debian Linux
• Google Cloud Platform
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Microsoft Azure Linux

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.117
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.12.58
• 6.12.59
• 6.17.0
• 6.17.1
• 6.17.2
• 6.17.3
• 6.17.4
• 6.17.5
• 6.17.6
• 6.17.7
• 6.17.8
• 6.17.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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