{"id":"CVE-2026-64379","state":"PUBLISHED","title":"smb: client: mask server-provided mode to 07777 in modefromsid","description":"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.","publishedAt":"2026-07-25T08:50:29.717Z","updatedAt":"2026-10-19T20:38:25.713Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"5f6f2241034f189c69d4d0b5f8fe24a0c25b0c14","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"ee2216dbdf0c677e89bb43e03247dba590ed00ef","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"f511807feee7cb29b61bdfa86472c7e9e2e5df94","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"08c600b7e1818539ba5efee4cdb06215c245ca78","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"b84e002e0df26bbc6cbd3ca01b8212601fe0ae7d","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"c6c484a7d5bff6b929a86d7ed5130f29834c6a0d","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"f80add1bfb3425100a325b14f19648e75669a954","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"e3d9c7160d483fc8f9e225aafad8ecbbc43f3151","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/cifsacl.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.4","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/cifsacl.c"]}],"references":["https://git.kernel.org/stable/c/5f6f2241034f189c69d4d0b5f8fe24a0c25b0c14","https://git.kernel.org/stable/c/ee2216dbdf0c677e89bb43e03247dba590ed00ef","https://git.kernel.org/stable/c/f511807feee7cb29b61bdfa86472c7e9e2e5df94","https://git.kernel.org/stable/c/08c600b7e1818539ba5efee4cdb06215c245ca78","https://git.kernel.org/stable/c/b84e002e0df26bbc6cbd3ca01b8212601fe0ae7d","https://git.kernel.org/stable/c/c6c484a7d5bff6b929a86d7ed5130f29834c6a0d","https://git.kernel.org/stable/c/f80add1bfb3425100a325b14f19648e75669a954","https://git.kernel.org/stable/c/e3d9c7160d483fc8f9e225aafad8ecbbc43f3151"],"weaknesses":["CWE-20"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64379.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64379","state":"PUBLISHED","datePublished":"2026-07-25T08:50:29.717Z","dateUpdated":"2026-10-19T20:38:25.713Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.784Z"},"containers":{"cna":{"title":"smb: client: mask server-provided mode to 07777 in modefromsid","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"5f6f2241034f189c69d4d0b5f8fe24a0c25b0c14","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"ee2216dbdf0c677e89bb43e03247dba590ed00ef","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"f511807feee7cb29b61bdfa86472c7e9e2e5df94","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"08c600b7e1818539ba5efee4cdb06215c245ca78","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"b84e002e0df26bbc6cbd3ca01b8212601fe0ae7d","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"c6c484a7d5bff6b929a86d7ed5130f29834c6a0d","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"f80add1bfb3425100a325b14f19648e75669a954","versionType":"git"},{"version":"e2f8fbfb8d09c06decde162090fac3ee220aa280","status":"affected","lessThan":"e3d9c7160d483fc8f9e225aafad8ecbbc43f3151","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/cifsacl.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.4","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/cifsacl.c"]}],"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"}],"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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:54:30.613Z"},"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"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64379","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:39:44.157534Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","lang":"en","type":"CWE","description":"CWE-20 Improper Input Validation"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:38:25.713Z"}}]}}}