{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68149","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-30T09:28:09.371Z","datePublished":"2026-08-10T11:59:14.645Z","dateUpdated":"2026-08-17T04:59:43.618Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T04:59:43.618Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs: preserve ACL_DONT_CACHE state in forget_cached_acl()\n\nThe ACL_DONT_CACHE state is meant to be a constant state for the inode\nfor filesystems that want to opt out of posix acl caching.\n\nCommit facd61053cff1 (\"fuse: fixes after adapting to new posix acl api\")\nused this facility to opt out of posix acl caching for fuse inodes with\nfuse server that does not negotiate FUSE_POSIX_ACL (fc->posix_acl).\n\nThe commit also takes care to gate the forget_all_cached_acls() call in\nfuse_set_acl() on fc->posix_acl because there is no need for it, but\nthere are other placed in fuse code which call forget_all_cached_acls()\nunconditional to fc->posix_acl and those cause the loss of the\nACL_DONT_CACHE state.\n\nThis is not only a functional bug. Properly timed, a get_acl() from this\nfuse filesystem can return a stale cached value, as was observed in tests,\nbecause set_acl() does not invalidate the unintentional acl cache.\n\nWe could fix this in fuse, but it actually makes no sense for the vfs\nhelper forget_cached_acl() to invalidate the ACL_DONT_CACHE state, so\nlet it not do that to fix fuse and future users of ACL_DONT_CACHE."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","baseScore":8.4,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Exploitation requires local VFS syscalls (getxattr, statx, open, read, write) on a FUSE-backed mount; the bug is in kernel ACL caching, not in a network protocol handler.\nAC:L - The attacker controls the full trigger sequence (stat/getattr to clear ACL_DONT_CACHE, getxattr to populate cache, ACL change, then access) and can drive timing with concurrent threads without depending on uncontrollable system state.\nPR:L - Any unprivileged local user who can mount or access a FUSE filesystem (fusermount, user namespaces, virtio-fs/SSHFS mounts with allow_other) can reach the vulnerable code paths on files within that mount.\nUI:N - Exploitation is fully attacker-driven through syscall sequences on the FUSE mount; no victim click, mount action, or other interactive cooperation is required beyond routine filesystem use.\nS:C - On virtio-fs/Kata/Firecracker shared host directories, stale kernel ACL enforcement can let a guest/container process access host-exported files beyond the permissions the host administrator intended, crossing that isolation boundary.\nC:H - Stale permissive cached ACLs cause check_acl()/posix_acl_permission() to authorize reads of files that should be denied after ACL tightening, enabling unauthorized disclosure of protected file contents on default_permissions mounts.\nI:H - The same stale ACL bypass lets an attacker obtain write permission enforced by the kernel VFS on files whose ACLs were subsequently restricted, enabling unauthorized modification of protected data.\nA:N - This is a stale-cache logic bug with no memory corruption, kernel crash, panic, or hang; observed impact is incorrect ACL enforcement and authorization bypass, not availability loss."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/posix_acl.c"],"versions":[{"version":"facd61053cff100973921d4d45d47cf53c747ec6","lessThan":"b98fad81f1202b0eb26aacf3ff4cc7a21ed3b5bf","status":"affected","versionType":"git"},{"version":"facd61053cff100973921d4d45d47cf53c747ec6","lessThan":"834ddf899484a2f23129080e8773bc04f4691d07","status":"affected","versionType":"git"},{"version":"facd61053cff100973921d4d45d47cf53c747ec6","lessThan":"a019b074903b3ad0a9726087efd0e8291452023b","status":"affected","versionType":"git"},{"version":"facd61053cff100973921d4d45d47cf53c747ec6","lessThan":"ca03a7984a34f48085fd013e0d2cf4e6420b4acf","status":"affected","versionType":"git"},{"version":"facd61053cff100973921d4d45d47cf53c747ec6","lessThan":"4b9a5458d02e214ef2b384124ca626e3e381d778","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/posix_acl.c"],"versions":[{"version":"6.2","status":"affected"},{"version":"0","lessThan":"6.2","status":"unaffected","versionType":"semver"},{"version":"6.6.148","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.101","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.42","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.6","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/b98fad81f1202b0eb26aacf3ff4cc7a21ed3b5bf"},{"url":"https://git.kernel.org/stable/c/834ddf899484a2f23129080e8773bc04f4691d07"},{"url":"https://git.kernel.org/stable/c/a019b074903b3ad0a9726087efd0e8291452023b"},{"url":"https://git.kernel.org/stable/c/ca03a7984a34f48085fd013e0d2cf4e6420b4acf"},{"url":"https://git.kernel.org/stable/c/4b9a5458d02e214ef2b384124ca626e3e381d778"}],"title":"fs: preserve ACL_DONT_CACHE state in forget_cached_acl()","x_generator":{"engine":"bippy-1.2.0"}}}}