SB20260928389 - Heap-based buffer overflow in Linux kernel smb client

Description

This security bulletin contains information about 1 vulnerability.

1) Heap-based buffer overflow (CVE-ID: CVE-2026-97555)

CWE-ID: CWE-122 - Heap-based Buffer Overflow

CVSSv4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a heap-based buffer overflow in the SMB client DACL owner/group rewrite logic when rewriting an existing DACL containing short SIDs with replacement owner or group SIDs obtained through a cifs.idmap upcall. A remote attacker can cause rewritten access control entries to exceed the allocated buffer to execute arbitrary code.

User interaction is required.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0ee150794c75bcd0be0e24ff3394f433cbae18cc
• https://git.kernel.org/stable/c/2a9aee9ef5622d58d8aafaa3263b3ffe70e2d9dd
• https://git.kernel.org/stable/c/7fa84c9ca690643f429ae2709584a47e74b572c9
• https://git.kernel.org/stable/c/fb736ab4fb8c4fdb8b2f9ccd3a62e03d11549ca1