Linux Kernel up to 6.18.26/7.0.3 tpm_buf_destroy buffer overflow

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 6.18.26/7.0.3. The affected element is the function tpm_buf_destroy. Such manipulation leads to buffer overflow. This vulnerability is referenced as CVE-2026-46096. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.26/7.0.3 and classified as critical. Affected by this issue is the function tpm_buf_destroy. The manipulation with an unknown input leads to a buffer overflow vulnerability. Using CWE to declare the problem leads to 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. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: tpm2-sessions: Fix missing tpm_buf_destroy() in tpm2_read_public() tpm2_read_public() calls tpm_buf_init() but fails to call tpm_buf_destroy() on two exit paths, leaking a page allocation: 1. When name_size() returns an error (unrecognized hash algorithm), the function returns directly without destroying the buffer. 2. On the success path, the buffer is never destroyed before returning. All other error paths in the function correctly call tpm_buf_destroy() before returning. Fix both by adding the missing tpm_buf_destroy() calls.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-46096 since 05/13/2026. The exploitation is known to be easy. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 06/26/2026).

Upgrading to version 6.18.27, 7.0.4 or 7.1-rc1 eliminates this vulnerability. Applying the patch f8775d9d9062da662cc861f9ff7722a65896d4cd/2f434be87e256fd58254f60ddf5d7d58e775ca0b/f0f75a3d98b7959a8677b6363e23190f3018636b 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.

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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
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 7.0.0
• 7.0.1
• 7.0.2
• 7.0.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

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