CVE-2026-64400

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Source
https://cve.org/CVERecord?id=CVE-2026-64400
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64400.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-64400
Downstream
Published
2026-07-25T08:50:43.655Z
Modified
2026-07-28T04:03:01.108925111Z
Severity
  • 8.6 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H CVSS Calculator
Summary
ksmbd: prevent path traversal bypass by restricting caseless retry
Details

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: prevent path traversal bypass by restricting caseless retry

ksmbdvfspathlookup() enforces LOOKUPBENEATH to restrict path resolution within the share root. When a crafted path attempts to escape the share boundary using parent-directory components ('..'), vfspathparent_lookup() detects this and immediately fails, returning -EXDEV.

However, a bug exists in __ksmbdvfskernpath() under caseless mode. The function fails to intercept the -EXDEV error and erroneously falls through to the caseless retry logic, which is intended only for genuinely missing files. During this retry process, the path is reconstructed, leading to an unintended LOOKUPBENEATH bypass that allows write-capable users to create zero-length files or directories outside the exported share.

Fix this by ensuring that the execution only proceeds to the caseless lookup retry when the error is specifically -ENOENT. Any other errors, such as -EXDEV from a path traversal attempt, must be returned immediately.

Database specific 
{
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64400.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
74d7970febf7e9005375aeda0df821d2edffc9f7
Fixed
8c9a4f1327eb71efbf14842e7b8a6d965077eb67
Fixed
54bab9ba5a9f156ffa9324fcbe5a356fd0242f95
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Last affected
019aae488dbc67c97a33db03652e20e2c9e3afa7
Last affected
6927ffe7479c72e7ebf885507227266a75f7c97d
Last affected
ef6cc1c465786b3e4e735d1ab8b616b3e94402df
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
5.15.145
Fixed
5.16
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
6.1.71
Fixed
6.2
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
6.3.10
Fixed
6.4

Affected versions

v2.*
v2.6.12-rc2
v2.6.12-rc3
v2.6.12-rc4
v2.6.13
v2.6.13-rc1
v2.6.13-rc2
v2.6.13-rc3
v2.6.13-rc4
v2.6.13-rc5
v2.6.13-rc6
v2.6.13-rc7
v2.6.14-rc1
v2.6.14-rc2
v2.6.14-rc3
v2.6.15-rc1
v2.6.15-rc2
v2.6.15-rc4
v2.6.15-rc5
v2.6.15-rc7
v2.6.16
v2.6.16-rc1
v2.6.16-rc2
v2.6.16-rc3
v2.6.16-rc4
v2.6.16-rc5
v2.6.16-rc6
v2.6.17
v2.6.17-rc1
v2.6.17-rc2
v2.6.17-rc3
v2.6.17-rc4
v2.6.17-rc5
v2.6.17-rc6
v2.6.18
v2.6.18-rc1
v2.6.18-rc2
v2.6.18-rc3
v2.6.18-rc5
v2.6.18-rc6
v2.6.19-rc1
v2.6.19-rc2
v2.6.20-rc1
v2.6.20-rc2
v2.6.20-rc3
v2.6.20-rc4
v2.6.20-rc5
v2.6.20-rc6
v2.6.20-rc7
v2.6.21
v2.6.21-rc1
v2.6.21-rc2
v2.6.21-rc3
v2.6.21-rc4
v2.6.21-rc5
v2.6.21-rc6
v2.6.21-rc7
v2.6.22
v2.6.22-rc1
v2.6.22-rc2
v2.6.22-rc3
v2.6.22-rc4
v2.6.22-rc5
v2.6.22-rc6
v2.6.22-rc7
v2.6.23
v2.6.23-rc1
v2.6.23-rc2
v2.6.23-rc3
v2.6.23-rc4
v2.6.23-rc5
v2.6.23-rc6
v2.6.23-rc7
v2.6.23-rc8
v2.6.23-rc9
v2.6.24
v2.6.24-rc1
v2.6.24-rc2
v2.6.24-rc3
v2.6.24-rc4
v2.6.24-rc5
v2.6.24-rc6
v2.6.24-rc7
v2.6.24-rc8
v2.6.25
v2.6.25-rc1
v2.6.25-rc2
v2.6.25-rc3
v2.6.25-rc4
v2.6.25-rc5
v2.6.25-rc6
v2.6.25-rc7
v2.6.25-rc8
v2.6.25-rc9
v2.6.26
v2.6.26-rc1
v2.6.26-rc2
v2.6.26-rc3
v2.6.26-rc4
v2.6.26-rc5
v2.6.26-rc6
v2.6.26-rc7
v2.6.26-rc8
v2.6.26-rc9
v2.6.27
v2.6.27-rc1
v2.6.27-rc2
v2.6.27-rc3
v2.6.27-rc4
v2.6.27-rc5
v2.6.27-rc6
v2.6.27-rc7
v2.6.27-rc8
v2.6.27-rc9
v2.6.28
v2.6.28-rc1
v2.6.28-rc2
v2.6.28-rc3
v2.6.28-rc4
v2.6.28-rc5
v2.6.28-rc6
v2.6.28-rc7
v2.6.28-rc8
v2.6.28-rc9
v2.6.29
v2.6.29-rc1
v2.6.29-rc2
v2.6.29-rc3
v2.6.29-rc4
v2.6.29-rc5
v2.6.29-rc6
v2.6.29-rc7
v2.6.29-rc8
v2.6.30
v2.6.30-rc1
v2.6.30-rc2
v2.6.30-rc3
v2.6.30-rc4
v2.6.30-rc5
v2.6.30-rc6
v2.6.30-rc7
v2.6.30-rc8
v2.6.31
v2.6.31-rc1
v2.6.31-rc2
v2.6.31-rc3
v2.6.31-rc4
v2.6.31-rc5
v2.6.31-rc6
v2.6.31-rc7
v2.6.31-rc8
v2.6.31-rc9
v2.6.32
v2.6.32-rc1
v2.6.32-rc2
v2.6.32-rc3
v2.6.32-rc4
v2.6.32-rc5
v2.6.32-rc6
v2.6.32-rc7
v2.6.32-rc8
v2.6.33
v2.6.33-rc1
v2.6.33-rc2
v2.6.33-rc3
v2.6.33-rc4
v2.6.33-rc5
v2.6.33-rc6
v2.6.33-rc7
v2.6.33-rc8
v2.6.34
v2.6.34-rc1
v2.6.34-rc2
v2.6.34-rc3
v2.6.34-rc4
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v2.6.35
v2.6.35-rc1
v2.6.35-rc2
v2.6.35-rc3
v2.6.35-rc4
v2.6.35-rc5
v2.6.35-rc6
v2.6.36
v2.6.36-rc1
v2.6.36-rc2
v2.6.36-rc3
v2.6.36-rc4
v2.6.36-rc5
v2.6.36-rc6
v2.6.36-rc7
v2.6.36-rc8
v2.6.37
v2.6.37-rc1
v2.6.37-rc2
v2.6.37-rc3
v2.6.37-rc4
v2.6.37-rc5
v2.6.37-rc6
v2.6.37-rc7
v2.6.37-rc8
v2.6.38
v2.6.38-rc1
v2.6.38-rc2
v2.6.38-rc3
v2.6.38-rc4
v2.6.38-rc5
v2.6.38-rc6
v2.6.38-rc7
v2.6.38-rc8
v2.6.39
v2.6.39-rc1
v2.6.39-rc2
v2.6.39-rc3
v2.6.39-rc4
v2.6.39-rc5
v2.6.39-rc6
v2.6.39-rc7
v3.*
v3.0
v3.0-rc1
v3.0-rc2
v3.0-rc3
v3.0-rc4
v3.0-rc5
v3.0-rc6
v3.0-rc7
v3.1
v3.1-rc1
v3.1-rc10
v3.1-rc2
v3.1-rc3
v3.1-rc4
v3.1-rc5
v3.1-rc6
v3.1-rc7
v3.1-rc8
v3.1-rc9
v3.10
v3.10-rc1
v3.10-rc2
v3.10-rc3
v3.10-rc4
v3.10-rc5
v3.10-rc6
v3.10-rc7
v3.11
v3.11-rc1
v3.11-rc2
v3.11-rc3
v3.11-rc4
v3.11-rc5
v3.11-rc6
v3.11-rc7
v3.12
v3.12-rc1
v3.12-rc2
v3.12-rc3
v3.12-rc4
v3.12-rc5
v3.12-rc6
v3.12-rc7
v3.13
v3.13-rc1
v3.13-rc2
v3.13-rc3
v3.13-rc4
v3.13-rc5
v3.13-rc6
v3.13-rc7
v3.13-rc8
v3.14
v3.14-rc1
v3.14-rc2
v3.14-rc3
v3.14-rc4
v3.14-rc5
v3.14-rc6
v3.14-rc7
v3.14-rc8
v3.15
v3.15-rc1
v3.15-rc2
v3.15-rc3
v3.15-rc4
v3.15-rc5
v3.15-rc6
v3.15-rc7
v3.15-rc8
v3.16
v3.16-rc1
v3.16-rc2
v3.16-rc3
v3.16-rc4
v3.16-rc5
v3.16-rc6
v3.16-rc7
v3.17
v3.17-rc1
v3.17-rc2
v3.17-rc3
v3.17-rc4
v3.17-rc5
v3.17-rc6
v3.17-rc7
v3.18
v3.18-rc1
v3.18-rc2
v3.18-rc3
v3.18-rc4
v3.18-rc5
v3.18-rc6
v3.18-rc7
v3.19
v3.19-rc1
v3.19-rc2
v3.19-rc3
v3.19-rc4
v3.19-rc5
v3.19-rc6
v3.19-rc7
v3.2
v3.2-rc1
v3.2-rc2
v3.2-rc3
v3.2-rc4
v3.2-rc5
v3.2-rc6
v3.2-rc7
v3.3
v3.3-rc1
v3.3-rc2
v3.3-rc3
v3.3-rc4
v3.3-rc5
v3.3-rc6
v3.3-rc7
v3.4
v3.4-rc1
v3.4-rc2
v3.4-rc3
v3.4-rc4
v3.4-rc5
v3.4-rc6
v3.4-rc7
v3.5
v3.5-rc1
v3.5-rc2
v3.5-rc3
v3.5-rc4
v3.5-rc5
v3.5-rc6
v3.5-rc7
v3.6
v3.6-rc1
v3.6-rc2
v3.6-rc3
v3.6-rc4
v3.6-rc5
v3.6-rc6
v3.6-rc7
v3.7
v3.7-rc1
v3.7-rc2
v3.7-rc3
v3.7-rc4
v3.7-rc5
v3.7-rc6
v3.7-rc7
v3.7-rc8
v3.8
v3.8-rc1
v3.8-rc2
v3.8-rc3
v3.8-rc4
v3.8-rc5
v3.8-rc6
v3.8-rc7
v3.9
v3.9-rc1
v3.9-rc2
v3.9-rc3
v3.9-rc4
v3.9-rc5
v3.9-rc6
v3.9-rc7
v3.9-rc8
v4.*
v4.0
v4.0-rc1
v4.0-rc2
v4.0-rc3
v4.0-rc4
v4.0-rc5
v4.0-rc6
v4.0-rc7
v4.1
v4.1-rc1
v4.1-rc2
v4.1-rc3
v4.1-rc4
v4.1-rc5
v4.1-rc6
v4.1-rc7
v4.1-rc8
v4.10
v4.10-rc1
v4.10-rc2
v4.10-rc3
v4.10-rc4
v4.10-rc5
v4.10-rc6
v4.10-rc7
v4.10-rc8
v4.11
v4.11-rc1
v4.11-rc2
v4.11-rc3
v4.11-rc4
v4.11-rc5
v4.11-rc6
v4.11-rc7
v4.11-rc8
v4.12
v4.12-rc1
v4.12-rc2
v4.12-rc3
v4.12-rc4
v4.12-rc5
v4.12-rc6
v4.12-rc7
v4.13
v4.13-rc1
v4.13-rc2
v4.13-rc3
v4.13-rc4
v4.13-rc5
v4.13-rc6
v4.13-rc7
v4.14
v4.14-rc1
v4.14-rc2
v4.14-rc3
v4.14-rc4
v4.14-rc5
v4.14-rc6
v4.14-rc7
v4.14-rc8
v4.15
v4.15-rc1
v4.15-rc2
v4.15-rc3
v4.15-rc4
v4.15-rc5
v4.15-rc6
v4.15-rc7
v4.15-rc8
v4.15-rc9
v4.16
v4.16-rc1
v4.16-rc2
v4.16-rc3
v4.16-rc4
v4.16-rc5
v4.16-rc6
v4.16-rc7
v4.17
v4.17-rc1
v4.17-rc2
v4.17-rc3
v4.17-rc4
v4.17-rc5
v4.17-rc6
v4.17-rc7
v4.18
v4.18-rc1
v4.18-rc2
v4.18-rc3
v4.18-rc4
v4.18-rc5
v4.18-rc6
v4.18-rc7
v4.18-rc8
v4.19
v4.19-rc1
v4.19-rc2
v4.19-rc3
v4.19-rc4
v4.19-rc5
v4.19-rc6
v4.19-rc7
v4.19-rc8
v4.2
v4.2-rc1
v4.2-rc2
v4.2-rc3
v4.2-rc4
v4.2-rc5
v4.2-rc6
v4.2-rc7
v4.2-rc8
v4.20
v4.20-rc1
v4.20-rc2
v4.20-rc3
v4.20-rc4
v4.20-rc5
v4.20-rc6
v4.20-rc7
v4.3
v4.3-rc1
v4.3-rc2
v4.3-rc3
v4.3-rc4
v4.3-rc5
v4.3-rc6
v4.3-rc7
v4.4
v4.4-rc1
v4.4-rc2
v4.4-rc3
v4.4-rc4
v4.4-rc5
v4.4-rc6
v4.4-rc7
v4.4-rc8
v4.5
v4.5-rc1
v4.5-rc2
v4.5-rc3
v4.5-rc4
v4.5-rc5
v4.5-rc6
v4.5-rc7
v4.6
v4.6-rc1
v4.6-rc2
v4.6-rc3
v4.6-rc4
v4.6-rc5
v4.6-rc6
v4.6-rc7
v4.7
v4.7-rc1
v4.7-rc2
v4.7-rc3
v4.7-rc4
v4.7-rc5
v4.7-rc6
v4.7-rc7
v4.8
v4.8-rc1
v4.8-rc2
v4.8-rc3
v4.8-rc4
v4.8-rc5
v4.8-rc6
v4.8-rc7
v4.8-rc8
v4.9
v4.9-rc1
v4.9-rc2
v4.9-rc3
v4.9-rc4
v4.9-rc5
v4.9-rc6
v4.9-rc7
v4.9-rc8
v5.*
v5.0
v5.0-rc1
v5.0-rc2
v5.0-rc3
v5.0-rc4
v5.0-rc5
v5.0-rc6
v5.0-rc7
v5.0-rc8
v5.1
v5.1-rc1
v5.1-rc2
v5.1-rc3
v5.1-rc4
v5.1-rc5
v5.1-rc6
v5.1-rc7
v5.10
v5.10-rc1
v5.10-rc2
v5.10-rc3
v5.10-rc4
v5.10-rc5
v5.10-rc6
v5.10-rc7
v5.11
v5.11-rc1
v5.11-rc2
v5.11-rc3
v5.11-rc4
v5.11-rc5
v5.11-rc6
v5.11-rc7
v5.12
v5.12-rc1
v5.12-rc1-dontuse
v5.12-rc2
v5.12-rc3
v5.12-rc4
v5.12-rc5
v5.12-rc6
v5.12-rc7
v5.12-rc8
v5.13
v5.13-rc1
v5.13-rc2
v5.13-rc3
v5.13-rc4
v5.13-rc5
v5.13-rc6
v5.13-rc7
v5.14
v5.14-rc1
v5.14-rc2
v5.14-rc3
v5.14-rc4
v5.14-rc5
v5.14-rc6
v5.14-rc7
v5.15
v5.15-rc1
v5.15-rc2
v5.15-rc3
v5.15-rc4
v5.15-rc5
v5.15-rc6
v5.15-rc7
v5.15.1
v5.15.10
v5.15.100
v5.15.101
v5.15.102
v5.15.103
v5.15.104
v5.15.105
v5.15.106
v5.15.107
v5.15.108
v5.15.109
v5.15.11
v5.15.110
v5.15.111
v5.15.112
v5.15.113
v5.15.114
v5.15.115
v5.15.116
v5.15.117
v5.15.118
v5.15.119
v5.15.12
v5.15.120
v5.15.121
v5.15.122
v5.15.123
v5.15.124
v5.15.125
v5.15.126
v5.15.127
v5.15.128
v5.15.129
v5.15.13
v5.15.130
v5.15.131
v5.15.132
v5.15.133
v5.15.134
v5.15.135
v5.15.136
v5.15.137
v5.15.138
v5.15.139
v5.15.14
v5.15.140
v5.15.141
v5.15.142
v5.15.143
v5.15.144
v5.15.15
v5.15.16
v5.15.17
v5.15.18
v5.15.19
v5.15.2
v5.15.20
v5.15.21
v5.15.22
v5.15.23
v5.15.24
v5.15.25
v5.15.26
v5.15.27
v5.15.28
v5.15.29
v5.15.3
v5.15.30
v5.15.31
v5.15.32
v5.15.33
v5.15.34
v5.15.35
v5.15.36
v5.15.37
v5.15.38
v5.15.39
v5.15.4
v5.15.40
v5.15.41
v5.15.42
v5.15.43
v5.15.44
v5.15.45
v5.15.46
v5.15.47
v5.15.48
v5.15.49
v5.15.5
v5.15.50
v5.15.51
v5.15.52
v5.15.53
v5.15.54
v5.15.55
v5.15.56
v5.15.57
v5.15.58
v5.15.59
v5.15.6
v5.15.60
v5.15.61
v5.15.62
v5.15.63
v5.15.64
v5.15.65
v5.15.66
v5.15.67
v5.15.68
v5.15.69
v5.15.7
v5.15.70
v5.15.71
v5.15.72
v5.15.73
v5.15.74
v5.15.75
v5.15.76
v5.15.77
v5.15.78
v5.15.79
v5.15.8
v5.15.80
v5.15.81
v5.15.82
v5.15.83
v5.15.84
v5.15.85
v5.15.86
v5.15.87
v5.15.88
v5.15.89
v5.15.9
v5.15.90
v5.15.91
v5.15.92
v5.15.93
v5.15.94
v5.15.95
v5.15.96
v5.15.97
v5.15.98
v5.15.99
v5.16
v5.16-rc1
v5.16-rc2
v5.16-rc3
v5.16-rc4
v5.16-rc5
v5.16-rc6
v5.16-rc7
v5.16-rc8
v5.17
v5.17-rc1
v5.17-rc2
v5.17-rc3
v5.17-rc4
v5.17-rc5
v5.17-rc6
v5.17-rc7
v5.17-rc8
v5.18
v5.18-rc1
v5.18-rc2
v5.18-rc3
v5.18-rc4
v5.18-rc5
v5.18-rc6
v5.18-rc7
v5.19
v5.19-rc1
v5.19-rc2
v5.19-rc3
v5.19-rc4
v5.19-rc5
v5.19-rc6
v5.19-rc7
v5.19-rc8
v5.2
v5.2-rc1
v5.2-rc2
v5.2-rc3
v5.2-rc4
v5.2-rc5
v5.2-rc6
v5.2-rc7
v5.3
v5.3-rc1
v5.3-rc2
v5.3-rc3
v5.3-rc4
v5.3-rc5
v5.3-rc6
v5.3-rc7
v5.3-rc8
v5.4
v5.4-rc1
v5.4-rc2
v5.4-rc3
v5.4-rc4
v5.4-rc5
v5.4-rc6
v5.4-rc7
v5.4-rc8
v5.5
v5.5-rc1
v5.5-rc2
v5.5-rc3
v5.5-rc4
v5.5-rc5
v5.5-rc6
v5.5-rc7
v5.6
v5.6-rc1
v5.6-rc2
v5.6-rc3
v5.6-rc4
v5.6-rc5
v5.6-rc6
v5.6-rc7
v5.7
v5.7-rc1
v5.7-rc2
v5.7-rc3
v5.7-rc4
v5.7-rc5
v5.7-rc6
v5.7-rc7
v5.8
v5.8-rc1
v5.8-rc2
v5.8-rc3
v5.8-rc4
v5.8-rc5
v5.8-rc6
v5.8-rc7
v5.9
v5.9-rc1
v5.9-rc2
v5.9-rc3
v5.9-rc4
v5.9-rc5
v5.9-rc6
v5.9-rc7
v5.9-rc8
v6.*
v6.0
v6.0-rc1
v6.0-rc2
v6.0-rc3
v6.0-rc4
v6.0-rc5
v6.0-rc6
v6.0-rc7
v6.1
v6.1-rc1
v6.1-rc2
v6.1-rc3
v6.1-rc4
v6.1-rc5
v6.1-rc6
v6.1-rc7
v6.1-rc8
v6.1.1
v6.1.10
v6.1.11
v6.1.12
v6.1.13
v6.1.14
v6.1.15
v6.1.16
v6.1.17
v6.1.18
v6.1.19
v6.1.2
v6.1.20
v6.1.21
v6.1.22
v6.1.23
v6.1.24
v6.1.25
v6.1.26
v6.1.27
v6.1.28
v6.1.29
v6.1.3
v6.1.30
v6.1.31
v6.1.32
v6.1.33
v6.1.34
v6.1.35
v6.1.36
v6.1.37
v6.1.38
v6.1.39
v6.1.4
v6.1.40
v6.1.41
v6.1.42
v6.1.43
v6.1.44
v6.1.45
v6.1.46
v6.1.47
v6.1.48
v6.1.49
v6.1.5
v6.1.50
v6.1.51
v6.1.52
v6.1.53
v6.1.54
v6.1.55
v6.1.56
v6.1.57
v6.1.58
v6.1.59
v6.1.6
v6.1.60
v6.1.61
v6.1.62
v6.1.63
v6.1.64
v6.1.65
v6.1.66
v6.1.67
v6.1.68
v6.1.69
v6.1.7
v6.1.70
v6.1.8
v6.1.9
v6.2
v6.2-rc1
v6.2-rc2
v6.2-rc3
v6.2-rc4
v6.2-rc5
v6.2-rc6
v6.2-rc7
v6.2-rc8
v6.3
v6.3-rc1
v6.3-rc2
v6.3-rc3
v6.3-rc4
v6.3-rc5
v6.3-rc6
v6.3-rc7
v6.3.1
v6.3.2
v6.3.3
v6.3.4
v6.3.5
v6.3.6
v6.3.7
v6.3.8
v6.3.9

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64400.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
6.4.0
Fixed
7.1.4

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64400.json"