CVE-2026-45252

medium

Description

When a fusefs file system implements extended attributes, the kernel may send a FUSE_LISTXATTR message to the userspace daemon to retrieve the list of extended attributes for a given file. The FUSE protocol requires the daemon to return a packed list of NUL-terminated strings. The fusefs kernel module calls strlen() on this daemon-supplied buffer without first verifying that the entire list is NUL-terminated. If a malicious daemon sends a non-NUL-terminated list, the fusefs kernel module may read beyond the end of one heap-allocated buffer and potentially write beyond the end of a second buffer. A malicious daemon could disclose up to 253 bytes of kernel heap memory, or it could inject up to 250 attacker-controlled bytes into unallocated kernel heap space.

References

https://security.freebsd.org/advisories/FreeBSD-SA-26:20.fusefs.asc

Details

Source: Mitre, NVD

Published: 2026-05-21

Updated: 2026-05-21

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:N/AC:L/Au:M/C:P/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 5.5

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:H

Severity: Medium

EPSS

EPSS: 0.00018