Linux Kernel MCTP Routing Vulnerability Allows Local Information Disclosure
A vulnerability in the Linux Kernel's MCTP routing component allows local attackers to disclose sensitive information, requiring high-privileged code execution to exploit.
A newly disclosed vulnerability in the Linux Kernel, identified as ZDI-26-690 and assigned CVE-2026-45930, presents a risk of sensitive information disclosure for local attackers. The exploitation of this flaw necessitates that an attacker already possesses high-privileged code execution capabilities on the target system.
The vulnerability stems from an uninitialized memory access within the kernel's handling of neighbor discovery messages. Specifically, the kernel fails to properly initialize memory regions before accessing them, leading to potential disclosure of sensitive data. This weakness could be chained with other vulnerabilities to achieve arbitrary code execution within the kernel's context.
The Zero Day Initiative (ZDI) has assigned this vulnerability a CVSS score of 6.0, categorizing it as moderate in severity. While direct exploitation by unprivileged users is not possible, its impact is amplified by the prerequisite of prior high-privilege access.
Linux has released a patch to address this vulnerability. The fix is available in the Linux kernel source code, with a specific commit referenced for developers and system administrators to track the resolution: a6a9bc544b675d8b5180f2718ec985ad267b5cbf.
The disclosure timeline indicates that the vulnerability was first reported to the vendor on December 4, 2025. Following a coordinated public release, the advisory was updated on September 14, 2026, marking the official public awareness of the issue.
This vulnerability was discovered and reported by Syed Faraz Abrar, associated with Zellic, and Pumpkin from the DEVCORE Research Team. Their contributions highlight the ongoing efforts by security researchers to identify and report vulnerabilities within critical open-source projects like the Linux Kernel.
While the vulnerability requires a high degree of prior access, its presence in the Linux Kernel underscores the importance of maintaining up-to-date systems and applying security patches promptly. Information disclosure vulnerabilities, even those with high-privilege prerequisites, can be critical components in multi-stage attack chains.