Directory Entry Overflow in Linux Kernel FUSE Implementation

CVE-2026-31694

What is CVE-2026-31694?

The Linux kernel's implementation of FUSE is vulnerable to a directory entry overflow due to improper validation of serialized directory entries. Specifically, the function fuse_add_dirent_to_cache() fails to verify whether a directory entry exceeds the maximum allowable size, allowing a malicious FUSE server to craft oversized directory entries. This oversight can lead to memory overflow situations, compromising the integrity of the kernel's memory management. By rejecting oversized directory entries prior to caching them, a more secure approach can effectively mitigate such vulnerabilities, safeguarding system stability and reliability.

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