CVE-2022-50668Network attack vector

Filesystem hang via non-atomic xattr cache flags

Published Dec 9, 2025 · Updated Aug 5, 2026

Race condition in the Linux kernel ext4 subsystem allows remote attackers to hang filesystems through concurrent xattr operations. Non-atomic updates to the shared e_reusable and e_referenced bitfield can lose a flag change, leaving an over-referenced mbcache entry marked reusable and trapping ext4_xattr_block_set in an infinite retry. A writable ext4-backed NFS or SMB export can expose the path without authentication; the result is a filesystem-wide hang, not data disclosure or modification.

CVSS severity7.5
High
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the Linux kernel ext4 subsystem allows remote attackers to hang filesystems through concurrent xattr operations. Non-atomic updates to the shared e_reusable and e_referenced bitfield can lose a flag change, leaving an over-referenced mbcache entry marked reusable and trapping ext4_xattr_block_set in an infinite retry. A writable ext4-backed NFS or SMB export can expose the path without authentication; the result is a filesystem-wide hang, not data disclosure or modification.

The record

CVE
CVE-2022-50668
Published
Dec 9, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 9, 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

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=4.6
  2. Affected versionversion=6048c64b26097a0ffbd966866b599f990e674e9b <127b80cefb941a81255c72f11081123f3a705369
  3. Affected versionversion=6048c64b26097a0ffbd966866b599f990e674e9b <1be16a0c2f10186df505e28b0cc92d7f3366e2a8
  4. Affected versionversion=6048c64b26097a0ffbd966866b599f990e674e9b <5bc0b2fda4b47c86278f7c6d30c211f425bf51cf
  5. Affected versionversion=6048c64b26097a0ffbd966866b599f990e674e9b <a44e84a9b7764c72896f7241a0ec9ac7e7ef38dd
  6. Affected versionversion=6048c64b26097a0ffbd966866b599f990e674e9b <af53065276376750dfac35a7248af18806404c5d
  7. Affected versionversion=6048c64b26097a0ffbd966866b599f990e674e9b <cc1538c693d25e282bed8c54b65c914a04023a78
  8. Affected versionversion=6048c64b26097a0ffbd966866b599f990e674e9b <efaa0ca678f56d47316a08030b2515678cebbc50

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.6; version=6048c64b26097a0ffbd966866b599f990e674e9b <127b80cefb941a81255c72f11081123f3a705369; version=6048c64b26097a0ffbd966866b599f990e674e9b <1be16a0c2f10186df505e28b0cc92d7f3366e2a8; version=6048c64b26097a0ffbd966866b599f990e674e9b <5bc0b2fda4b47c86278f7c6d30c211f425bf51cf; version=6048c64b26097a0ffbd966866b599f990e674e9b <a44e84a9b7764c72896f7241a0ec9ac7e7ef38dd; version=6048c64b26097a0ffbd966866b599f990e674e9b <af53065276376750dfac35a7248af18806404c5d; version=6048c64b26097a0ffbd966866b599f990e674e9b <cc1538c693d25e282bed8c54b65c914a04023a78; version=6048c64b26097a0ffbd966866b599f990e674e9b <efaa0ca678f56d47316a08030b2515678cebbc50

Published CVSS scores

7.5Linux kernel CVE teamCVSS:3.1/AV:N/AC:L/PR:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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