CVE-2026-48004

CVE Details

Release Date:	2026-08-19
Impact:	Moderate	What is this?

Description

9pfs: fix missing rename lock in v9fs_co_readdir_many (CVE-2026-48004) v9fs_co_readdir_many() dispatches do_readdir_many() to a worker thread that reads V9fsFidState's path.data without holding a rename lock. A concurrent rename request, e.g. of its parent dir, causes the FID's absolute path to be altered by freeing the old path string and assigning a new one. This causes a heap-use-after-free race condition while do_readdir_many() is still accessing the old object. This allows a DoS by an unprivileged guest user. Fix this by wrapping the worker thread dispatch block within a pair of v9fs_path_read_lock() and v9fs_path_unlock() calls, like it's done at other places.

See more information about CVE-2026-48004 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	4.7
Vector String:	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Version:	3.1
Attack Vector:	Local
Attack Complexity:	High
Privileges Required:	Low
User Interaction:	None
Scope:	Unchanged
Confidentiality Impact:	None
Integrity Impact:	None
Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 9 (qemu-kvm)	ELSA-2026-500220	2026-08-19