CVE-2022-49999

Filesystem corruption via concurrent extent unpinning

Published Jun 18, 2025 · Updated Aug 5, 2026

A race in the Linux btrfs space cache allows local users to corrupt filesystem metadata through concurrent file operations. Overlapping transaction commits let btrfs_cache_block_group and btrfs_finish_extent_commit add the same freed extent to the in-memory cache twice. Write access to a mounted btrfs filesystem is required; double allocation can expose or overwrite file blocks, and persisted duplicate free ranges can crash the next mount.

CVSS severity7.8
High
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A race in the Linux btrfs space cache allows local users to corrupt filesystem metadata through concurrent file operations. Overlapping transaction commits let btrfs_cache_block_group and btrfs_finish_extent_commit add the same freed extent to the in-memory cache twice. Write access to a mounted btrfs filesystem is required; double allocation can expose or overwrite file blocks, and persisted duplicate free ranges can crash the next mount.

The record

CVE
CVE-2022-49999
Published
Jun 18, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-787
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=5.12
  2. Affected versionversion=d0c2f4fa555e70324ec2a129b822ab58f172cc62 <92dc4c1a8e58bcc7a183a4c86b055c24cc88d967
  3. Affected versionversion=d0c2f4fa555e70324ec2a129b822ab58f172cc62 <a2e54eb64229f07f917b05d0c323604fda9b89f7
  4. Affected versionversion=d0c2f4fa555e70324ec2a129b822ab58f172cc62 <ced8ecf026fd8084cf175530ff85c76d6085d715

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.12; version=d0c2f4fa555e70324ec2a129b822ab58f172cc62 <92dc4c1a8e58bcc7a183a4c86b055c24cc88d967; version=d0c2f4fa555e70324ec2a129b822ab58f172cc62 <a2e54eb64229f07f917b05d0c323604fda9b89f7; version=d0c2f4fa555e70324ec2a129b822ab58f172cc62 <ced8ecf026fd8084cf175530ff85c76d6085d715

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8Linux kernel CVE teamCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5SUSECVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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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