CVE-2026-72186

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-72186", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.911Z", "datePublished": "2026-08-15T05:53:48.127Z", "dateUpdated": "2026-08-17T05:41:16.318Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:41:16.318Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: make system files immutable to prevent corruption\n\nWhen a system file such as $Bitmap is exposed via show_sys_files and\nwritten from userspace, the volume is corrupted and, because the cluster\nallocator scans $Bitmap through the same inode's page cache, a write to\n$Bitmap also deadlocks writeback against the folio it already holds locked.\n\nThese files are maintained by the driver itself and have no valid reason\nto be written through the file interface. Mark base metadata files\n(mft_no < FILE_first_user) as immutable during inode read so the VFS\nrejects write, mmap, truncate and unlink with -EPERM. Directories are\nskipped so the root and $Extend remain usable. Internal metadata updates\ndo not go through the VFS write path and are unaffected."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL"}, "scenarios": [{"lang": "en", "value": "AV:N - fs/ntfs registers ntfs_export_ops; remote nfsd/ksmbd write RPCs reach ntfs_file_write_iter on $Bitmap, and dual-boot/shared NTFS volumes are commonly rw-mounted and network-exported on NAS/hybrid servers.\nAC:L - Without S_IMMUTABLE, opening $Bitmap by name and writing is deterministic; expanding $Bitmap triggers ntfs_attr_map_cluster while lcnalloc holds the same folio locked, deadlocking writeback as documented in the fix commit.\nPR:N - Exploitation needs only permission to write on a mounted NTFS volume (default i_mode 0777 with fmask=0, uid/gid mount options, authenticated SMB/NFS client, or guest write); no CAP_SYS_ADMIN or init-namespace root is required at trigger time.\nUI:N - Once an administrator has rw-mounted and optionally exported the NTFS volume, the attacker issues normal write/mmap/truncate/unlink to $Bitmap or other mft_no<FILE_first_user files; no per-attack victim interaction is required.\nS:U - Impact is on-disk NTFS metadata corruption and kernel thread deadlock within the host filesystem/kernel authority; this is standard filesystem abuse, not a VM escape, container breakout, or IOMMU boundary bypass.\nC:N - The flaw is attacker-initiated writes to exposed system files and resulting metadata corruption; it does not perform kernel out-of-bounds reads, use-after-free, or other memory-disclosure primitives.\nI:H - Writing $Bitmap (or $MFT, $LogFile, $Boot, etc.) lets an attacker directly control cluster-allocation state, causing arbitrary on-disk metadata corruption and steered overwrites of live file data clusters across the volume.\nA:H - Concurrent $Bitmap writes deadlock the cluster allocator against writeback on the same folio, hanging kernel I/O threads, and corrupted allocation bitmaps can render the NTFS volume inconsistent and unusable on remount."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/ntfs/inode.c"], "versions": [{"version": "af0db57d4293cc9fe6ce99fb5592dc2652228c9d", "lessThan": "8f313e92522ac41d273ea137db13ea8a8df2beed", "status": "affected", "versionType": "git"}, {"version": "af0db57d4293cc9fe6ce99fb5592dc2652228c9d", "lessThan": "f72df3a4c33b64de3418ec74d1ad4f028e09d161", "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/ntfs/inode.c"], "versions": [{"version": "7.1", "status": "affected"}, {"version": "0", "lessThan": "7.1", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.5", "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": "7.1", "versionEndExcluding": "7.1.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/8f313e92522ac41d273ea137db13ea8a8df2beed"}, {"url": "https://git.kernel.org/stable/c/f72df3a4c33b64de3418ec74d1ad4f028e09d161"}], "title": "ntfs: make system files immutable to prevent corruption", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/ntfs/inode.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "8f313e92522ac41d273ea137db13ea8a8df2beed", "status": "affected", "version": "af0db57d4293cc9fe6ce99fb5592dc2652228c9d", "versionType": "git"}, {"lessThan": "f72df3a4c33b64de3418ec74d1ad4f028e09d161", "status": "affected", "version": "af0db57d4293cc9fe6ce99fb5592dc2652228c9d", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/ntfs/inode.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "7.1"}, {"lessThan": "7.1", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: make system files immutable to prevent corruption\n\nWhen a system file such as $Bitmap is exposed via show_sys_files and\nwritten from userspace, the volume is corrupted and, because the cluster\nallocator scans $Bitmap through the same inode's page cache, a write to\n$Bitmap also deadlocks writeback against the folio it already holds locked.\n\nThese files are maintained by the driver itself and have no valid reason\nto be written through the file interface. Mark base metadata files\n(mft_no < FILE_first_user) as immutable during inode read so the VFS\nrejects write, mmap, truncate and unlink with -EPERM. Directories are\nskipped so the root and $Extend remain usable. Internal metadata updates\ndo not go through the VFS write path and are unaffected."}], "id": "CVE-2026-72186", "lastModified": "2026-08-17T06:18:19.193", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.1, "baseSeverity": "CRITICAL", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.2, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-15T06:21:36.973", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8f313e92522ac41d273ea137db13ea8a8df2beed"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f72df3a4c33b64de3418ec74d1ad4f028e09d161"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: ntfs: make system files immutable to prevent corruption", "id": "2516609", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2516609"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-552", "details": ["A flaw was found in the Linux kernel's NTFS driver. A local user could exploit this by writing to specific system files, such as $Bitmap, which are exposed through the show_sys_files interface. This unauthorized write access can lead to file system corruption and potentially cause a system deadlock, impacting data integrity and system availability."], "name": "CVE-2026-72186", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-72186\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-72186\nhttps://lore.kernel.org/linux-cve-announce/2026081540-CVE-2026-72186-e2ba@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[af0db57d4293cc9fe6ce99fb5592dc2652228c9d,8f313e92522ac41d273ea137db13ea8a8df2beed)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[af0db57d4293cc9fe6ce99fb5592dc2652228c9d,f72df3a4c33b64de3418ec74d1ad4f028e09d161)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "7.1"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,7.1)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.5,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc3,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-15T09:15:04.759728+00:00", "updated": "2026-08-22T09:00:10.805337+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-284", "CWE-552", "CWE-749"]}