CVE-2025-37956Network attack vector

Kernel memory disclosure and corruption via empty rename

Published May 20, 2025 · Updated Aug 5, 2026

Denial of service in the Linux kernel's ksmbd component allows remote authenticated users to crash the host through a crafted SMB rename. A FILE_RENAME_INFORMATION request containing only a UTF-16 NUL leaves the new-name qstr uninitialized before __d_alloc uses its pointer and length. Reachability requires an SMB session, writable share, and FILE_DELETE handle; the unchecked state can disclose kernel memory, corrupt a dentry, or panic the host.

CVSS severity8.8
High
EPSS probability0.35%
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 the Linux kernel's ksmbd component allows remote authenticated users to crash the host through a crafted SMB rename. A FILE_RENAME_INFORMATION request containing only a UTF-16 NUL leaves the new-name qstr uninitialized before __d_alloc uses its pointer and length. Reachability requires an SMB session, writable share, and FILE_DELETE handle; the unchecked state can disclose kernel memory, corrupt a dentry, or panic the host.

The record

CVE
CVE-2025-37956
Published
May 20, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 20, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=0626e6641f6b467447c81dd7678a69c66f7746cf <53e3e5babc0963a92d856a5ec0ce92c59f54bc12
  2. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <6ee551672c8cf36108b0cfba92ec0c7c28ac3439
  3. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <c57301e332cc413fe0a7294a90725f4e21e9549d
  4. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <d7f2c00acb1ef64304fd40ac507e9213ff1d9b5c
  5. Affected versionversion=5.15

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0626e6641f6b467447c81dd7678a69c66f7746cf <53e3e5babc0963a92d856a5ec0ce92c59f54bc12; version=0626e6641f6b467447c81dd7678a69c66f7746cf <6ee551672c8cf36108b0cfba92ec0c7c28ac3439; version=0626e6641f6b467447c81dd7678a69c66f7746cf <c57301e332cc413fe0a7294a90725f4e21e9549d; version=0626e6641f6b467447c81dd7678a69c66f7746cf <d7f2c00acb1ef64304fd40ac507e9213ff1d9b5c; version=5.15

Published CVSS scores

5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
8.8LinuxCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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