CVEvulnerability

CVE-2026-31694

7.8 HIGH Published 2026-05-01 Modified 2026-10-23 Official page ↗
Status
Analyzed
Published
2026-05-01
Last modified
2026-10-23
Assigner
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Description

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.

Affected configurations

• linux linux kernel (>= 6.15 < 6.18.25) • linux linux kernel (>= 6.19 < 7.0.2) • linux linux kernel 7.1 • siemens simatic s7-1500 tm mfp firmware

References