Linux Kernel up to 6.19.8 ksmbd generate_smb3signingkey privilege escalation

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 6.1.166/6.6.129/6.12.77/6.18.19/6.19.8. This affects the function generate_smb3signingkey of the component ksmbd. The manipulation results in an unknown weakness. This vulnerability is reported as CVE-2026-43377. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.1.166/6.6.129/6.12.77/6.18.19/6.19.8. Affected is the function generate_smb3signingkey of the component ksmbd. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ksmbd: Don't log keys in SMB3 signing and encryption key generation When KSMBD_DEBUG_AUTH logging is enabled, generate_smb3signingkey() and generate_smb3encryptionkey() log the session, signing, encryption, and decryption key bytes. Remove the logs to avoid exposing credentials.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-43377 since 05/01/2026. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 07/27/2026).

Upgrading to version 6.1.167, 6.6.130, 6.12.78, 6.18.20 or 6.19.9 eliminates this vulnerability. Applying the patch 4084ed720d7d5f4e975c9e4a6267a552dad3b24a/fec5c70b82af3f59f15bb984df94e5ad1fccfb1e/3fe2d9ec166b7df9a8df6c0fdcfc210572e27e3f/407cc37c21d51f9b9d4d20204b04890880cfa6ae/c6b01b997a2094969e315f1ebfc1d64b8ae2163d/441336115df26b966575de56daf7107ed474faed is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1454). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Red Hat OpenShift
• Microsoft Azure Linux
• Open Source Linux Kernel
• Proxmox Virtual Environment

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.166
• 6.6.129
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.12.58
• 6.12.59
• 6.12.60
• 6.12.61
• 6.12.62
• 6.12.63
• 6.12.64
• 6.12.65
• 6.12.66
• 6.12.67
• 6.12.68
• 6.12.69
• 6.12.70
• 6.12.71
• 6.12.72
• 6.12.73
• 6.12.74
• 6.12.75
• 6.12.76
• 6.12.77
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5
• 6.19.6
• 6.19.7
• 6.19.8

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

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