Linux Kernel up to 6.18.9 rust_binder out-of-bounds

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.18.9. It has been declared as critical. The impacted element is an unknown function of the component rust_binder. Such manipulation leads to out-of-bounds. This vulnerability is referenced as CVE-2026-23194. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.9 and classified as problematic. Affected by this issue is some unknown processing of the component rust_binder. 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. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: rust_binder: correctly handle FDA objects of length zero Fix a bug where an empty FDA (fd array) object with 0 fds would cause an out-of-bounds error. The previous implementation used `skip == 0` to mean "this is a pointer fixup", but 0 is also the correct skip length for an empty FDA. If the FDA is at the end of the buffer, then this results in an attempt to write 8-bytes out of bounds. This is caught and results in an EINVAL error being returned to userspace. The pattern of using `skip == 0` as a special value originates from the C-implementation of Binder. As part of fixing this bug, this pattern is replaced with a Rust enum. I considered the alternate option of not pushing a fixup when the length is zero, but I think it's cleaner to just get rid of the zero-is-special stuff. The root cause of this bug was diagnosed by Gemini CLI on first try. I used the following prompt: > There appears to be a bug in @drivers/android/binder/thread.rs where > the Fixups oob bug is triggered with 316 304 316 324. This implies > that we somehow ended up with a fixup where buffer A has a pointer to > buffer B, but the pointer is located at an index in buffer A that is > out of bounds. Please investigate the code to find the bug. You may > compare with @drivers/android/binder.c that implements this correctly.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-23194 since 01/13/2026. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 299100 (Linux Distros Unpatched Vulnerability : CVE-2026-23194), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.10 eliminates this vulnerability. Applying the patch 598fe3ff32e43918ed8a062f55432b3d23e6340c/8f589c9c3be539d6c2b393c82940c3783831082f 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 (299100) and CERT Bund (WID-SEC-2026-0421). Once again VulDB remains the best source 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
• 6.18.7
• 6.18.8
• 6.18.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Once again VulDB remains the best source for vulnerability data.

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