CVE-2026-31706 - Vulnerability Analysis

Overview

Linux kernel ksmbd contains a heap allocation vulnerability caused by unvalidated num_aces value in smb_inherit_dacl(), letting authenticated clients cause large memory allocation and potential overflow, exploit requires tampered parent directory's security.NTACL xattr.

Severity & Score

Impact

Authenticated attackers can cause large memory allocations and potential kernel memory corruption, leading to denial of service or system instability.

Mitigation

Update to the latest Linux kernel version containing the patch that validates num_aces and hardens ACE walk in smb_inherit_dacl().

References

• https://git.kernel.org/stable/c/3e4e2ea2a781018ed5d75f969e3e5606beb66e48
• https://git.kernel.org/stable/c/3e5360b422dd741cb315654a191fa73869a37414
• https://git.kernel.org/stable/c/59c32abaaec9cdd6164811c7e864e72f7554b82d
• https://git.kernel.org/stable/c/063a7409b0de46d7c770b65bb0338e6fdb3b1f0a

Related Resources

• Vulnerability Intelligence Dashboard
• Credential Scanner