CVE-2023-53427

Kernel use-after-free via failed MR allocation

Published Sep 18, 2025 · Updated Sep 18, 2025

Use-after-free in the Linux kernel allows local users to corrupt kernel memory when an SMB Direct mount encounters MR allocation failure. The connection path initializes MR recovery work only after allocation and leaves failed MRs listed, so smbd_destroy flushes uninitialized work and reads freed entries. Reachability requires permission to initiate the CIFS mount, an SMB Direct connection, and MR allocation failure; the published trace establishes a warning and invalid read, not code execution.

CVSS severity7.8
High
EPSS probability0.15%
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 the Linux kernel allows local users to corrupt kernel memory when an SMB Direct mount encounters MR allocation failure. The connection path initializes MR recovery work only after allocation and leaves failed MRs listed, so smbd_destroy flushes uninitialized work and reads freed entries. Reachability requires permission to initiate the CIFS mount, an SMB Direct connection, and MR allocation failure; the published trace establishes a warning and invalid read, not code execution.

The record

CVE
CVE-2023-53427
Published
Sep 18, 2025
Updated
Sep 18, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2025Record 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=4.16
  2. Affected versionversion=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <275a3d2b9408fc4895e342f772cab9a89960546e
  3. Affected versionversion=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <2d0c4f5f618f58eba03385363717703bee873c64
  4. Affected versionversion=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <3524d6da0fe88aee79f06be6572955d16ad76b39
  5. Affected versionversion=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <3e161c2791f8e661eed24a2c624087084d910215
  6. Affected versionversion=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <41832c62a75dad530dc5a2856c92ae5459d497e5
  7. Affected versionversion=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <7cbd5bdb5bd4404a5da4309521134b42c65846c0
  8. Affected versionversion=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <cfd85a0922c4696d768965e686ad805a58d9d834

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.16; version=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <275a3d2b9408fc4895e342f772cab9a89960546e; version=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <2d0c4f5f618f58eba03385363717703bee873c64; version=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <3524d6da0fe88aee79f06be6572955d16ad76b39; version=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <3e161c2791f8e661eed24a2c624087084d910215; version=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <41832c62a75dad530dc5a2856c92ae5459d497e5; version=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <7cbd5bdb5bd4404a5da4309521134b42c65846c0; version=c7398583340a6d82b8bb7f7f21edcde27dc6a898 <cfd85a0922c4696d768965e686ad805a58d9d834

Published CVSS scores

7.8CanonicalCVSS:3.1/AV:L/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1499.004Endpoint Denial of Service: Application 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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