CVE-2021-47660

Local denial of service via replay leak

Published Feb 26, 2025 · Updated May 11, 2026

Memory leak in the Linux kernel NTFS3 driver allows local users to consume kernel memory through NTFS journal replay. In fs/ntfs3/fslog.c, an error branch in log_replay() returns directly instead of entering the shared cleanup path, leaving log, ra, and log->one_page_buf allocated. The path requires local access and NTFS journal replay; repeated triggering consumes kernel memory until service is interrupted, but the public record does not describe a reproducible trigger.

CVSS severity5.5
Medium
EPSS probability0.24%
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 NTFS3 driver allows local users to consume kernel memory through NTFS journal replay. In fs/ntfs3/fslog.c, an error branch in log_replay() returns directly instead of entering the shared cleanup path, leaving log, ra, and log->one_page_buf allocated. The path requires local access and NTFS journal replay; repeated triggering consumes kernel memory until service is interrupted, but the public record does not describe a reproducible trigger.

The record

CVE
CVE-2021-47660
Published
Feb 26, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 26, 2025CVE 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

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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=5.15
  2. Affected versionversion=b46acd6a6a627d876898e1c84d3f84902264b445 <2c97519ed6b4239594c58ddacf3d0d576cf070cc
  3. Affected versionversion=b46acd6a6a627d876898e1c84d3f84902264b445 <bc4a1d384a04c6dba9312e1421a9f9f7c03339a4
  4. Affected versionversion=b46acd6a6a627d876898e1c84d3f84902264b445 <d8be98ab88250dc12a98efdb703792a537b0eac3
  5. Affected versionversion=b46acd6a6a627d876898e1c84d3f84902264b445 <e589f9b7078e1c0191613cd736f598e81d2390de

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15; version=b46acd6a6a627d876898e1c84d3f84902264b445 <2c97519ed6b4239594c58ddacf3d0d576cf070cc; version=b46acd6a6a627d876898e1c84d3f84902264b445 <bc4a1d384a04c6dba9312e1421a9f9f7c03339a4; version=b46acd6a6a627d876898e1c84d3f84902264b445 <d8be98ab88250dc12a98efdb703792a537b0eac3; version=b46acd6a6a627d876898e1c84d3f84902264b445 <e589f9b7078e1c0191613cd736f598e81d2390de

Published CVSS scores

5.5CISA ADP VulnrichmentCVSS: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-401Missing Release of Memory after Effective Lifetime

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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