CVE-2025-22037Public exploitNetwork attack vector

Unauthenticated crash or hang via preauth NULL dereference

Published Apr 16, 2025 · Updated Aug 5, 2026

NULL pointer dereference in Linux kernel ksmbd allows remote attackers to crash or hang SMB servers via malformed negotiation. alloc_preauth_hash() copies Preauth_HashValue through conn->preauth_info after a failed SMB 3.1.1 negotiate leaves that pointer unallocated. Exposure requires ksmbd to be loaded or built in and listening; triggering causes a kernel oops, followed by a reboot or progressive hang depending on panic settings.

CVSS severity7.5
High
EPSS probability67.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in Linux kernel ksmbd allows remote attackers to crash or hang SMB servers via malformed negotiation. alloc_preauth_hash() copies Preauth_HashValue through conn->preauth_info after a failed SMB 3.1.1 negotiate leaves that pointer unallocated. Exposure requires ksmbd to be loaded or built in and listening; triggering causes a kernel oops, followed by a reboot or progressive hang depending on panic settings.

The record

CVE
CVE-2025-22037
Published
Apr 16, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 16, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <8f216b33a5e1b3489c073b1ea1b3d7cb63c8dc4d
  2. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <b8eb243e670ecf30e91524dd12f7260dac07d335
  3. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <c8b5b7c5da7d0c31c9b7190b4a7bba5281fc4780
  4. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <ca8bed31edf728a662ef9d6f39f50e7a7dc2b5ad
  5. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <cce57cd8c5dead24127cf2308fdd60fcad2d6ba6
  6. Affected versionversion=5.15

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0626e6641f6b467447c81dd7678a69c66f7746cf <8f216b33a5e1b3489c073b1ea1b3d7cb63c8dc4d; version=0626e6641f6b467447c81dd7678a69c66f7746cf <b8eb243e670ecf30e91524dd12f7260dac07d335; version=0626e6641f6b467447c81dd7678a69c66f7746cf <c8b5b7c5da7d0c31c9b7190b4a7bba5281fc4780; version=0626e6641f6b467447c81dd7678a69c66f7746cf <ca8bed31edf728a662ef9d6f39f50e7a7dc2b5ad; version=0626e6641f6b467447c81dd7678a69c66f7746cf <cce57cd8c5dead24127cf2308fdd60fcad2d6ba6; version=5.15

Published CVSS scores

7.5Linux kernel CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.8Trend Micro Zero Day InitiativeCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

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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