CVE-2024-40938

Local denial of service via mount-point d_parent walk

Published Jul 12, 2024 · Updated May 11, 2026

Denial of service in affected Linux kernels allows local users to trigger a kernel warning by linking a root mount point. Landlock collect_domain_accesses() wrongly walks the source directory d_parent when the source is itself the mount point, before VFS rejects the link. With panic_on_warn enabled, the warning crashes the host; otherwise, the attempted link cannot succeed and no confidentiality or integrity impact is reported.

CVSS severity5.5
Medium
EPSS probability0.25%
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 affected Linux kernels allows local users to trigger a kernel warning by linking a root mount point. Landlock collect_domain_accesses() wrongly walks the source directory d_parent when the source is itself the mount point, before VFS rejects the link. With panic_on_warn enabled, the warning crashes the host; otherwise, the attempted link cannot succeed and no confidentiality or integrity impact is reported.

The record

CVE
CVE-2024-40938
Published
Jul 12, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 12, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=5.19
  2. Affected versionversion=b91c3e4ea756b12b7d992529226edce1cfd854d7 <88da52ccd66e65f2e63a6c35c9dff55d448ef4dc
  3. Affected versionversion=b91c3e4ea756b12b7d992529226edce1cfd854d7 <b6e5e696435832b33e40775f060ef5c95f4fda1f
  4. Affected versionversion=b91c3e4ea756b12b7d992529226edce1cfd854d7 <c7618c7b0b8c45bcef34410cc1d1e953eb17f8f6
  5. Affected versionversion=b91c3e4ea756b12b7d992529226edce1cfd854d7 <cc30d05b34f9a087a6928d09b131f7b491e9ab11

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.19; version=b91c3e4ea756b12b7d992529226edce1cfd854d7 <88da52ccd66e65f2e63a6c35c9dff55d448ef4dc; version=b91c3e4ea756b12b7d992529226edce1cfd854d7 <b6e5e696435832b33e40775f060ef5c95f4fda1f; version=b91c3e4ea756b12b7d992529226edce1cfd854d7 <c7618c7b0b8c45bcef34410cc1d1e953eb17f8f6; version=b91c3e4ea756b12b7d992529226edce1cfd854d7 <cc30d05b34f9a087a6928d09b131f7b491e9ab11

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
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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