CVE-2023-53867Network attack vector

Client crash via capability-trimming use-after-free

Published Dec 24, 2025 · Updated Dec 24, 2025

Use-after-free in Linux CephFS kernel clients allows remote attackers controlling an MDS to crash clients through capability messages. After ceph_iterate_session_caps releases s_cap_lock, another thread can remove a capability before callbacks reuse its stale memory. Reachability requires a mounted CephFS kernel client and a malicious, compromised, or spoofed MDS; stale reads and writes can disclose or corrupt kernel memory or cause an oops.

CVSS severity9.8
Critical
EPSS probability0.52%
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 CephFS kernel clients allows remote attackers controlling an MDS to crash clients through capability messages. After ceph_iterate_session_caps releases s_cap_lock, another thread can remove a capability before callbacks reuse its stale memory. Reachability requires a mounted CephFS kernel client and a malicious, compromised, or spoofed MDS; stale reads and writes can disclose or corrupt kernel memory or cause an oops.

The record

CVE
CVE-2023-53867
Published
Dec 24, 2025
Updated
Dec 24, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 24, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 24, 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 <2b2515b8095cf2149bef44383a99d5b5677f1831
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <448875a73e16ba7d81dec9274ce9d33a12d092fb
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <aaf67de78807c59c35bafb5003d4fb457c764800
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ae6e935618d99cdba11eab4714092e7e5f13cf7e

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2b2515b8095cf2149bef44383a99d5b5677f1831; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <448875a73e16ba7d81dec9274ce9d33a12d092fb; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <aaf67de78807c59c35bafb5003d4fb457c764800; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ae6e935618d99cdba11eab4714092e7e5f13cf7e

Published CVSS scores

9.8Linux Kernel CNACVSS:3.1/AV:N/AC:L/PR:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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