CVE-2025-22040Network attack vector

Kernel compromise via multichannel session use-after-free

Published Apr 16, 2025 · Updated Aug 5, 2026

Use-after-free in Linux ksmbd allows remote authenticated users to compromise the kernel through a multichannel SMB session race. During second-channel binding, session setup can retain a session after ksmbd_sessions_deregister frees it, then add the connection to the freed session's channel list. The attacker must authenticate, bind a second channel, and disconnect the first during setup; the attacker-controlled race corrupts kernel memory.

CVSS severity8.8
High
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux ksmbd allows remote authenticated users to compromise the kernel through a multichannel SMB session race. During second-channel binding, session setup can retain a session after ksmbd_sessions_deregister frees it, then add the connection to the freed session's channel list. The attacker must authenticate, bind a second channel, and disconnect the first during setup; the attacker-controlled race corrupts kernel memory.

The record

CVE
CVE-2025-22040
Published
Apr 16, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1210
Attack vector
network
Privileges
authenticated

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

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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 <3980770cb1470054e6400fd97668665975726737
  2. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <596407adb9af1ee75fe7c7529607783d31b66e7f
  3. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <7dfbd4c43eed91dd2548a95236908025707a8dfd
  4. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <9069939d762138e232a6f79e3e1462682ed6a17d
  5. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <94c281721d4ed2d972232414b91d98a6f5bdb16b
  6. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <fa4cdb8cbca7d6cb6aa13e4d8d83d1103f6345db
  7. Affected versionversion=5.15

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0626e6641f6b467447c81dd7678a69c66f7746cf <3980770cb1470054e6400fd97668665975726737; version=0626e6641f6b467447c81dd7678a69c66f7746cf <596407adb9af1ee75fe7c7529607783d31b66e7f; version=0626e6641f6b467447c81dd7678a69c66f7746cf <7dfbd4c43eed91dd2548a95236908025707a8dfd; version=0626e6641f6b467447c81dd7678a69c66f7746cf <9069939d762138e232a6f79e3e1462682ed6a17d; version=0626e6641f6b467447c81dd7678a69c66f7746cf <94c281721d4ed2d972232414b91d98a6f5bdb16b; version=0626e6641f6b467447c81dd7678a69c66f7746cf <fa4cdb8cbca7d6cb6aa13e4d8d83d1103f6345db; version=5.15

Published CVSS scores

7.8CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8Linux kernel CNACVSS: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

CWE-416Use After Free
T1210Exploitation of Remote Services

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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