CVE-2022-49938

Memory exhaustion via leaked SMB response buffers

Published Jun 18, 2025 · Updated May 23, 2026

Memory leak in the Linux kernel CIFS client allows local users to exhaust memory through repeated SMB2 dialect mismatches. SMB2_negotiate returns directly on a mismatched server dialect after allocating a response buffer from a mempool, bypassing the neg_exit cleanup path. Exploitation requires local access to initiate CIFS connections to a server that returns an unrequested dialect; repetition can interrupt service by depleting kernel memory.

CVSS severity5.5
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in the Linux kernel CIFS client allows local users to exhaust memory through repeated SMB2 dialect mismatches. SMB2_negotiate returns directly on a mismatched server dialect after allocating a response buffer from a mempool, bypassing the neg_exit cleanup path. Exploitation requires local access to initiate CIFS connections to a server that returns an unrequested dialect; repetition can interrupt service by depleting kernel memory.

The record

CVE
CVE-2022-49938
Published
Jun 18, 2025
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 18, 2025CVE publishedPublication date reported by the CVE source.
  2. May 23, 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=1ae6f05d4204d3a128bb9ba2c42e2a6c4ac687f1
  2. Affected versionversion=4.13.5 <4.14
  3. Affected versionversion=4.14
  4. Affected versionversion=9764c02fcbad40001fd3f63558d918e4d519bb75 <27893dfc1285f80f80f46b3b8c95f5d15d2e66d0
  5. Affected versionversion=9764c02fcbad40001fd3f63558d918e4d519bb75 <38a6b469bf22f153282fbe7d702a24e9eb43f50e
  6. Affected versionversion=9764c02fcbad40001fd3f63558d918e4d519bb75 <9e3c9efa7caf16e5acc05eab5e4d0a714e1610b0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1ae6f05d4204d3a128bb9ba2c42e2a6c4ac687f1; version=4.13.5 <4.14; version=4.14; version=9764c02fcbad40001fd3f63558d918e4d519bb75 <27893dfc1285f80f80f46b3b8c95f5d15d2e66d0; version=9764c02fcbad40001fd3f63558d918e4d519bb75 <38a6b469bf22f153282fbe7d702a24e9eb43f50e; version=9764c02fcbad40001fd3f63558d918e4d519bb75 <9e3c9efa7caf16e5acc05eab5e4d0a714e1610b0

Published CVSS scores

5.5NISTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.6NISTAV:L/AC:L/Au:S/C:N/I:N/A:C

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499.004Application or System Exploitation

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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