CVE-2026-31694

EIP tracks 1 public exploit for CVE-2026-31694. PoCs published by 0xCyberstan.

AI-analyzed exploit summary This repository contains a functional local privilege escalation (LPE) exploit for CVE-2026-31694, targeting a missing bounds check in the FUSE readdir cache implementation in Linux kernels 6.15 and later. The exploit demonstrates both a marker mode to prove the out-of-bounds write and an LPE mode that manipulates /etc/passwd to achieve root access.

In the Linux kernel, the following vulnerability has been resolved: fuse: reject oversized dirents in page cache fuse_add_dirent_to_cache() computes a serialized dirent size from the server-controlled namelen field and copies the dirent into a single page-cache page. The existing logic only checks whether the dirent fits in the remaining space of the current page and advances to a fresh page if not. It never checks whether the dirent itself exceeds PAGE_SIZE. As a result, a malicious FUSE server can return a dirent with namelen=4095, producing a serialized record size of 4120 bytes. On 4 KiB page systems this causes memcpy() to overflow the cache page by 24 bytes into the following kernel page. Reject dirents that cannot fit in a single page before copying them into the readdir cache.