Vulnary
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Critical· 9.8official fix available

CVE-2023-52440

A critical flaw in the Linux kernel's SMB server (ksmbd) can cause a memory overflow when processing certain authentication blobs. This could let an attacker crash the system or potentially execute code. The issue has been fixed in recent kernel releases.

publishedFeb 21, 2024
last modifiedAug 4, 2026
sourcesNVD
severity · cvss
9.8
critical · how bad it is
exploitation · epss
22%
97th percentile · chance of exploitation in 30 days
(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →
auto-deletes from the system
counting…on Sep 5, 2026

An official fix is available, so this entry is kept for 30 days and then removed automatically.

01

Who is affected

Linux kernel, any distribution using the ksmbd SMB server component, especially versions before the patch.

02

Real-world impact

An attacker could crash the system or potentially run arbitrary code by sending a crafted SMB authentication blob.

03

Why this severity

The CVSS score of 9.8 reflects that the vulnerability is exploitable over the network, requires no user interaction, and can lead to complete compromise of confidentiality, integrity, and availability.

04

What to do about it

official fix available
recommended steps
  1. 01Upgrade to a Linux kernel version that includes the ksmbd patch.

NVD-referenced vendor advisory

05

Timeline

  1. Feb 21, 2024 · Feb 21, 2024
    Published
    Disclosed and added to the National Vulnerability Database.
  2. Aug 4, 2026 · 2d ago
    Advisory updated
    The NVD record was last revised.
  3. Aug 6, 2026 · 8h ago
    Official fix available
    A vendor patch or mitigation now exists — see the remediation steps above.
06

How it’s attacked

Attack vectorNetwork (remote)
Attack complexityLow
Privileges requiredNone
User interactionNone needed
ScopeUnchanged
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
07

References & advisories

(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →