CVE-2026-68149
Received Received - Intake

ACL State Corruption in Linux Kernel

Vulnerability report for CVE-2026-68149, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-08-10

Last updated on: 2026-08-10

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: fs: preserve ACL_DONT_CACHE state in forget_cached_acl() The ACL_DONT_CACHE state is meant to be a constant state for the inode for filesystems that want to opt out of posix acl caching. Commit facd61053cff1 ("fuse: fixes after adapting to new posix acl api") used this facility to opt out of posix acl caching for fuse inodes with fuse server that does not negotiate FUSE_POSIX_ACL (fc->posix_acl). The commit also takes care to gate the forget_all_cached_acls() call in fuse_set_acl() on fc->posix_acl because there is no need for it, but there are other placed in fuse code which call forget_all_cached_acls() unconditional to fc->posix_acl and those cause the loss of the ACL_DONT_CACHE state. This is not only a functional bug. Properly timed, a get_acl() from this fuse filesystem can return a stale cached value, as was observed in tests, because set_acl() does not invalidate the unintentional acl cache. We could fix this in fuse, but it actually makes no sense for the vfs helper forget_cached_acl() to invalidate the ACL_DONT_CACHE state, so let it not do that to fix fuse and future users of ACL_DONT_CACHE.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-08-10
Last Modified
2026-08-10
Generated
2026-08-10
AI Q&A
2026-08-10
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux_kernel linux_kernel *

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability in the Linux kernel involves the improper handling of the ACL_DONT_CACHE state in the forget_cached_acl() function. The ACL_DONT_CACHE state is meant to prevent caching of POSIX ACLs for filesystems that opt out of it, such as FUSE. A recent commit introduced a bug where other parts of the FUSE code unconditionally call forget_all_cached_acls(), which removes the ACL_DONT_CACHE state. This can lead to stale ACL values being returned, as set_acl() fails to invalidate the unintended cache.

Impact Analysis

If you use a FUSE filesystem that does not negotiate FUSE_POSIX_ACL, this vulnerability could cause your system to return outdated or incorrect ACL values. This might lead to improper access control, where users or processes gain unauthorized access to files or directories due to stale permissions being enforced.

Mitigation Strategies

Update the Linux kernel to the latest patched version to resolve the ACL_DONT_CACHE state issue in the VFS layer.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-68149. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart