{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64379", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.784Z", "datePublished": "2026-07-25T08:50:29.717Z", "dateUpdated": "2026-08-17T04:54:30.613Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:54:30.613Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: mask server-provided mode to 07777 in modefromsid\n\nWhen modefromsid is active, parse_dacl() applies the server-provided\nsub_auth[2] value from the NFS mode SID to cf_mode without masking to\n07777. Apply the correct masking, same as in the read path." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - A malicious or compromised SMB server can supply the crafted NFS mode SID through a network-delivered QUERY_INFO security descriptor.\nAC:L - With modefromsid enabled, the server directly controls sub_auth[2], and the invalid inode-type bits are applied deterministically without a race or memory-layout dependency.\nPR:N - The attacker acting as the SMB server needs no privileges on the client; client authentication to the share is a victim-side condition rather than an attacker privilege.\nUI:R - A victim administrator or service must mount the SMB share with modefromsid, or subsequently access a crafted object on an existing mount.\nS:U - The corrupted mode and resulting VFS behavior remain within the Linux kernel's existing security authority and do not cross a VM, IOMMU, or sandbox boundary.\nC:N - The flaw only injects bits into the 16-bit mode field and provides no out-of-bounds read, memory disclosure, or direct mechanism for returning client data to the attacker.\nI:L - The attacker can alter S_IFMT bits in cf_mode and thereby change the inode's perceived type and selected VFS operations, but this is a constrained metadata modification rather than an arbitrary write or control-flow primitive.\nA:H - Forging the root or widespread inode types can prevent the share from mounting or render its objects unusable; for CIFS-root or critical SMB-backed deployments this can cause complete service availability loss." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/cifsacl.c" ], "versions": [ { "version": "e2f8fbfb8d09c06decde162090fac3ee220aa280", "lessThan": "5f6f2241034f189c69d4d0b5f8fe24a0c25b0c14", "status": "affected", "versionType": "git" }, { "version": "e2f8fbfb8d09c06decde162090fac3ee220aa280", "lessThan": "ee2216dbdf0c677e89bb43e03247dba590ed00ef", "status": "affected", "versionType": "git" }, { "version": "e2f8fbfb8d09c06decde162090fac3ee220aa280", "lessThan": "f511807feee7cb29b61bdfa86472c7e9e2e5df94", "status": "affected", "versionType": "git" }, { "version": "e2f8fbfb8d09c06decde162090fac3ee220aa280", "lessThan": "08c600b7e1818539ba5efee4cdb06215c245ca78", "status": "affected", "versionType": "git" }, { "version": "e2f8fbfb8d09c06decde162090fac3ee220aa280", "lessThan": "b84e002e0df26bbc6cbd3ca01b8212601fe0ae7d", "status": "affected", "versionType": "git" }, { "version": "e2f8fbfb8d09c06decde162090fac3ee220aa280", "lessThan": "c6c484a7d5bff6b929a86d7ed5130f29834c6a0d", "status": "affected", "versionType": "git" }, { "version": "e2f8fbfb8d09c06decde162090fac3ee220aa280", "lessThan": "f80add1bfb3425100a325b14f19648e75669a954", "status": "affected", "versionType": "git" }, { "version": "e2f8fbfb8d09c06decde162090fac3ee220aa280", "lessThan": "e3d9c7160d483fc8f9e225aafad8ecbbc43f3151", "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/smb/client/cifsacl.c" ], "versions": [ { "version": "5.4", "status": "affected" }, { "version": "0", "lessThan": "5.4", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.4", "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": "5.4", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.12.96" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "7.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/5f6f2241034f189c69d4d0b5f8fe24a0c25b0c14" }, { "url": "https://git.kernel.org/stable/c/ee2216dbdf0c677e89bb43e03247dba590ed00ef" }, { "url": "https://git.kernel.org/stable/c/f511807feee7cb29b61bdfa86472c7e9e2e5df94" }, { "url": "https://git.kernel.org/stable/c/08c600b7e1818539ba5efee4cdb06215c245ca78" }, { "url": "https://git.kernel.org/stable/c/b84e002e0df26bbc6cbd3ca01b8212601fe0ae7d" }, { "url": "https://git.kernel.org/stable/c/c6c484a7d5bff6b929a86d7ed5130f29834c6a0d" }, { "url": "https://git.kernel.org/stable/c/f80add1bfb3425100a325b14f19648e75669a954" }, { "url": "https://git.kernel.org/stable/c/e3d9c7160d483fc8f9e225aafad8ecbbc43f3151" } ], "title": "smb: client: mask server-provided mode to 07777 in modefromsid", "x_generator": { "engine": "bippy-1.2.0" } } } }