CVE-2023-2593Network attack vector

Denial of service via endless TCP receive retries

Published Jul 30, 2025 · Updated Jun 29, 2026

Denial of service in Linux Kernel ksmbd before 6.2-rc3 allows remote attackers to exhaust memory through unauthenticated TCP connections. ksmbd_tcp_readv treats -EAGAIN from kernel_recvmsg() as an unlimited retry, so connection threads never exit and their memory remains allocated. The ksmbd server must be enabled on TCP port 445, and exploitation depends on repeatedly driving receives into -EAGAIN; availability is the only reported impact.

CVSS severity5.9
Medium
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux Kernel ksmbd before 6.2-rc3 allows remote attackers to exhaust memory through unauthenticated TCP connections. ksmbd_tcp_readv treats -EAGAIN from kernel_recvmsg() as an unlimited retry, so connection threads never exit and their memory remains allocated. The ksmbd server must be enabled on TCP port 445, and exploitation depends on repeatedly driving receives into -EAGAIN; availability is the only reported impact.

The record

CVE
CVE-2023-2593
Published
Jul 30, 2025
Updated
Jun 29, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-835, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 30, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <6.2-rc3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0 <6.2-rc3

Published CVSS scores

5.9Red HatCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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