{ "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" } } } }