Out-of-bounds read in Linux kernel - CVE-2026-68100

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Main Vulnerability Database Vulnerabilities #VU142225

Out-of-bounds read in Linux kernel - CVE-2026-68100

Published: August 12, 2026


Vulnerability identifier: #VU142225
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-68100
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote user to disclose sensitive information.

The vulnerability exists due to an out-of-bounds read in set_ntacl_dacl() when processing a crafted security descriptor during SMB2_QUERY_INFO(SecInfo=DACL). A remote user can send a crafted SMB2_SET_INFO request containing a malformed ACE and later trigger SMB2_QUERY_INFO to disclose sensitive information.

The issue affects inodes carrying a POSIX access ACL, and the malformed security descriptor is stored raw after being accepted because parse_dacl() breaks on a bad ACE instead of returning an error.


Affected software

Linux kernel
Ubuntu
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)

How to mitigate CVE-2026-68100

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1

External References

Related Security Bulletins