Linux Kernel up to 6.18.18/6.19.8 rust_binder toctou

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.18.18/6.19.8. It has been declared as critical. This issue affects some unknown processing of the component rust_binder. The manipulation results in toctou. This vulnerability is identified as CVE-2026-43433. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.18/6.19.8. It has been classified as critical. Affected is some unknown processing of the component rust_binder. The manipulation with an unknown input leads to a toctou vulnerability. CWE is classifying the issue as CWE-367. The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: rust_binder: avoid reading the written value in offsets array When sending a transaction, its offsets array is first copied into the target proc's vma, and then the values are read back from there. This is normally fine because the vma is a read-only mapping, so the target process cannot change the value under us. However, if the target process somehow gains the ability to write to its own vma, it could change the offset before it's read back, causing the kernel to misinterpret what the sender meant. If the sender happens to send a payload with a specific shape, this could in the worst case lead to the receiver being able to privilege escalate into the sender. The intent is that gaining the ability to change the read-only vma of your own process should not be exploitable, so remove this TOCTOU read even though it's unexploitable without another Binder bug.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-43433 since 05/01/2026. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 315710 (Linux Distros Unpatched Vulnerability : CVE-2026-43433), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.19 or 6.19.9 eliminates this vulnerability. Applying the patch e19afb53f7723b3bd22224f2b0c7dcfa70bb973f/3672141c93b7a0c0132bf5d5021a4b7f1d663aaa/4cb9e13fec0de7c942f5f927469beb8e48ddd20f 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 vulnerability database at Tenable (315710). VulDB is the best source for vulnerability data and more expert information about this specific topic.

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
• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5
• 6.19.6
• 6.19.7
• 6.19.8

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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