What is CVE-2023-3866?

CVE-2023-3866 is a high-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2025-08-16.

How severe is CVE-2023-3866?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2023-3866 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

NULL pointer dereference in Linux

CVE-2023-3866

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate session id and tree id in the compound request This patch validate session id and tree id in compound request. If first operation in the compound is SMB2 ECHO request, ksmbd bypass session and tree validation. So work->sess and work->tcon could be NULL. If secound request in the compound access work->sess or tcon, It cause NULL pointer dereferecing error.

EPSS: 0.156 (96.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Linux — versions 0626e6641f6b467447c81dd7678a69c66f7746cf, 5.15, 0
Linux Linux_kernel — versions 6.4

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

Public proof-of-concept exploits

References

416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)

Frequently asked questions

What is CVE-2023-3866?: CVE-2023-3866 is a high-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2025-08-16.
How severe is CVE-2023-3866?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2023-3866 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.