CVE-2023-53246

System crash via CIFS DFS referral traversal

Published Sep 15, 2025 · Updated Sep 15, 2025

NULL pointer dereference in affected Linux kernel releases allows local users to crash the system by traversing a DFS referral link. With CONFIG_CIFS_DFS_UPCALL disabled, CIFS still marks referral dentries for automount even though cifs_dfs_d_automount is NULL, so VFS follow_automount dereferences it. The condition requires a kernel built without that option and access sufficient to traverse a mounted DFS referral; the documented consequence is a system crash.

CVSS severity5.5
Medium
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

NULL pointer dereference in affected Linux kernel releases allows local users to crash the system by traversing a DFS referral link. With CONFIG_CIFS_DFS_UPCALL disabled, CIFS still marks referral dentries for automount even though cifs_dfs_d_automount is NULL, so VFS follow_automount dereferences it. The condition requires a kernel built without that option and access sufficient to traverse a mounted DFS referral; the documented consequence is a system crash.

The record

CVE
CVE-2023-53246
Published
Sep 15, 2025
Updated
Sep 15, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 2025Record 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <179a88a8558bbf42991d361595281f3e45d7edfc
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1e144b68208e98fd4602c842a7149ba5f41d87fb
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <26a32a212bc540f4773cd6af8cf73e967d72569c
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <657d7c215ca974d366ab1808213f716e1e3aa950
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8afb1fabcec1929db46977e84baeee0cc0e79242
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8cd7dbc9c46d51e00a0a8372e07cc1cbb8d24a77
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b64305185b76f1d5145ce594ff48f3f0e70695bd
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b7d854c33ab48e55fc233699bbefe39ec9bb5c05

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <179a88a8558bbf42991d361595281f3e45d7edfc; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1e144b68208e98fd4602c842a7149ba5f41d87fb; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <26a32a212bc540f4773cd6af8cf73e967d72569c; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <657d7c215ca974d366ab1808213f716e1e3aa950; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8afb1fabcec1929db46977e84baeee0cc0e79242; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8cd7dbc9c46d51e00a0a8372e07cc1cbb8d24a77; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b64305185b76f1d5145ce594ff48f3f0e70695bd; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b7d854c33ab48e55fc233699bbefe39ec9bb5c05

Published CVSS scores

5.5CanonicalCVSS: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.

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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-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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