Vulnerability · Published May 21, 2026 · Assigned by freebsd
CVE-2026-45252Heap overflow in FUSE_LISTXATTR
Medium 5.5
In plain English
A medium-severity heap buffer overflow in FreeBSD from FreeBSD. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities).
Official 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.
Affected products (as reported)
Weakness: CWE-122 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:H