# CVE-2023-32251: Kernel: ksmbd brute force delay bypass via asynchronous requests

Status: published. Published: 2025-07-31. Updated: 2026-11-09.

A vulnerability has been identified in the Linux kernel's ksmbd component (kernel SMB/CIFS server). A security control designed to prevent dictionary attacks, which introduces a 5-second delay during session setup, can be bypassed through the use of asynchronous requests. This bypass negates the intended anti-brute-force protection, potentially allowing attackers to conduct dictionary attacks more efficiently against user credentials or other authentication mechanisms.

## Remediation

No remediation reported in collected sources

## Affected products and versions

-  /  (linux): ≥ 0; < 5.15.145 (affected, semvar); ≥ 6.0.0; < 6.0.* (affected, semvar); ≥ 6.1.0; < 6.1.29 (affected, semvar); ≥ 6.2.0; < 6.2.16 (affected, semvar); ≥ 6.3.0; < 6.3.2 (affected, semvar). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10 (kernel): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (kernel): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (kernel): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (kernel-rt): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (kernel): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (kernel-rt): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (kernel): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (kernel-rt): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 3.7 (low); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.49% as of 2026-11-08; percentile 42.67%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-307

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/security/cve/CVE-2023-32251 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2385852 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b096d97f47326b1e2dbdef1c91fab69ffda54d17 (CNA: redhat)

- https://www.zerodayinitiative.com/advisories/ZDI-23-699/ (CNA: redhat)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2023-32251; retrieved 2026-11-09; source updated 2026-11-09

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2023-32251; retrieved 2026-11-09; source updated Not reported

Revision: fe1e21a560cfeac33654cfba46dd4efb0ccbe4a6fcdc057b8316c84e07b358cc

Canonical: https://y2.dev/cve/CVE-2023-32251

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