Linux Kernel up to 6.18.15/6.19.5 mailbox mchp_ipc_get_cluster_aggr_irq out-of-bounds

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.18.15/6.19.5. It has been rated as critical. This vulnerability affects the function mchp_ipc_get_cluster_aggr_irq of the component mailbox. The manipulation leads to out-of-bounds. This vulnerability is traded as CVE-2026-43274. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.15/6.19.5. It has been rated as problematic. This issue affects the function mchp_ipc_get_cluster_aggr_irq of the component mailbox. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: mailbox: mchp-ipc-sbi: fix out-of-bounds access in mchp_ipc_get_cluster_aggr_irq() The cluster_cfg array is dynamically allocated to hold per-CPU configuration structures, with its size based on the number of online CPUs. Previously, this array was indexed using hartid, which may be non-contiguous or exceed the bounds of the array, leading to out-of-bounds access. Switch to using cpuid as the index, as it is guaranteed to be within the valid range provided by for_each_online_cpu().

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-43274 since 05/01/2026. Technical details are known, but no exploit is available.

Upgrading to version 6.18.16 or 6.19.6 eliminates this vulnerability. Applying the patch 95438699c92947155823dcd3918049a07f3cd867/0442b6229e2eedc95a6d3d18ce75dec7f5b5377c/f7c330a8c83c9b0332fd524097eaf3e69148164d 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.

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

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
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

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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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