{"id":"CVE-2026-64393","state":"PUBLISHED","title":"ksmbd: run set info with opener credentials","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: run set info with opener credentials\n\nSMB2 SET_INFO handlers call path-based VFS helpers after checking the\naccess mask granted to the SMB handle. Those helpers perform their owner,\ninode permission and LSM checks using the current ksmbd worker credentials.\n\nRun the complete SET_INFO dispatch with the credentials captured when the\nhandle was opened. This also removes the separate security information\ncredential setup and keeps all SET_INFO classes under one credential scope.\n\nDirect override_creds() is used because it can nest with the request\ncredential overrides already used by rename and link helpers.","publishedAt":"2026-07-25T08:50:39.239Z","updatedAt":"2026-08-17T04:54:46.744Z","severity":{"score":9.1,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"5cbabf3a71575cd31bc7785d92d4ab42338a654b","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"b35afd5cf8fab236ef21117e42ee45691d4ffa7b","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"0ce682867fd506f61f40c76bde7e4205bde34e87","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"20ee516a62989a8d505ee432f9e59525ea23984e","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"8cc9ec711f5255167247a9ab6a7179b787426ed7","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"b383bcad3d2fe634b26efbce53e22bbb5753a520","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/smb2pdu.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"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/server/smb2pdu.c"]}],"references":["https://git.kernel.org/stable/c/5cbabf3a71575cd31bc7785d92d4ab42338a654b","https://git.kernel.org/stable/c/b35afd5cf8fab236ef21117e42ee45691d4ffa7b","https://git.kernel.org/stable/c/0ce682867fd506f61f40c76bde7e4205bde34e87","https://git.kernel.org/stable/c/20ee516a62989a8d505ee432f9e59525ea23984e","https://git.kernel.org/stable/c/8cc9ec711f5255167247a9ab6a7179b787426ed7","https://git.kernel.org/stable/c/b383bcad3d2fe634b26efbce53e22bbb5753a520"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64393.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64393","state":"PUBLISHED","datePublished":"2026-07-25T08:50:39.239Z","dateUpdated":"2026-08-17T04:54:46.744Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.785Z"},"containers":{"cna":{"title":"ksmbd: run set info with opener credentials","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: run set info with opener credentials\n\nSMB2 SET_INFO handlers call path-based VFS helpers after checking the\naccess mask granted to the SMB handle. Those helpers perform their owner,\ninode permission and LSM checks using the current ksmbd worker credentials.\n\nRun the complete SET_INFO dispatch with the credentials captured when the\nhandle was opened. This also removes the separate security information\ncredential setup and keeps all SET_INFO classes under one credential scope.\n\nDirect override_creds() is used because it can nest with the request\ncredential overrides already used by rename and link helpers."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"5cbabf3a71575cd31bc7785d92d4ab42338a654b","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"b35afd5cf8fab236ef21117e42ee45691d4ffa7b","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"0ce682867fd506f61f40c76bde7e4205bde34e87","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"20ee516a62989a8d505ee432f9e59525ea23984e","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"8cc9ec711f5255167247a9ab6a7179b787426ed7","versionType":"git"},{"version":"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9","status":"affected","lessThan":"b383bcad3d2fe634b26efbce53e22bbb5753a520","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/server/smb2pdu.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"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/server/smb2pdu.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/5cbabf3a71575cd31bc7785d92d4ab42338a654b"},{"url":"https://git.kernel.org/stable/c/b35afd5cf8fab236ef21117e42ee45691d4ffa7b"},{"url":"https://git.kernel.org/stable/c/0ce682867fd506f61f40c76bde7e4205bde34e87"},{"url":"https://git.kernel.org/stable/c/20ee516a62989a8d505ee432f9e59525ea23984e"},{"url":"https://git.kernel.org/stable/c/8cc9ec711f5255167247a9ab6a7179b787426ed7"},{"url":"https://git.kernel.org/stable/c/b383bcad3d2fe634b26efbce53e22bbb5753a520"}],"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 - The vulnerable SMB2 SET_INFO handler is remotely reachable through ksmbd over TCP/445 or SMB Direct.\nAC:L - An attacker can deterministically open a handle and send a crafted SET_INFO request; no race or condition outside the attacker’s control is required.\nPR:N - Although a valid SMB session, writable tree, and suitable handle are required, ksmbd supports passwordless guest sessions on writable shares, making exploitation possible without attacker privileges in a reasonable deployment.\nUI:N - The attacker directly opens the handle and submits the SET_INFO request without any victim action.\nS:U - The bypass affects files and services governed by the same host kernel and filesystem security authority, without crossing a virtualization or sandbox boundary.\nC:N - The flaw provides unauthorized mutation through metadata, xattr, and truncation operations but does not itself disclose file contents or kernel memory.\nI:H - Privileged worker credentials can bypass opener UID, group, capability, inode, and LSM checks, permitting protected metadata changes and destructive truncation of an affected file.\nA:H - Repeated SET_INFO requests can truncate critical files or corrupt security-relevant metadata and xattrs, potentially disabling dependent services or exhausting filesystem resources."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:54:46.744Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.12.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}