CVE-2026-31556

Local denial of service via retained dquot lock

Published Apr 24, 2026 · Updated Apr 24, 2026

Denial of service in Linux Kernel XFS quota scrub allows local users to hang later quota operations through a quota-scrub error path. In xchk_quota_item, a false return from xchk_fblock_process_error causes an early return without releasing dq->q_qlock, leaving the dquot locked. Exploitation requires local low-privilege access and the relevant XFS scrub error path; the lock leak can deadlock later quota operations without reported confidentiality or integrity impact.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux Kernel XFS quota scrub allows local users to hang later quota operations through a quota-scrub error path. In xchk_quota_item, a false return from xchk_fblock_process_error causes an early return without releasing dq->q_qlock, leaving the dquot locked. Exploitation requires local low-privilege access and the relevant XFS scrub error path; the lock leak can deadlock later quota operations without reported confidentiality or integrity impact.

The record

CVE
CVE-2026-31556
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 24, 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=6.8
  2. Affected versionversion=7d1f0e167a067ed741dec08b7614d76893422b04 <268378b6ad20569af0d1957992de1c8b16c6e900
  3. Affected versionversion=7d1f0e167a067ed741dec08b7614d76893422b04 <3b0c3414b308e6822cda90bf99f7eac94d4cca2b
  4. Affected versionversion=7d1f0e167a067ed741dec08b7614d76893422b04 <d128fc0c5c2b19224927d4fd2a46c2fe6a1f606f
  5. Affected versionversion=7d1f0e167a067ed741dec08b7614d76893422b04 <e822f535273af0e8968eab7acc0cea0b90dd25af

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.8; version=7d1f0e167a067ed741dec08b7614d76893422b04 <268378b6ad20569af0d1957992de1c8b16c6e900; version=7d1f0e167a067ed741dec08b7614d76893422b04 <3b0c3414b308e6822cda90bf99f7eac94d4cca2b; version=7d1f0e167a067ed741dec08b7614d76893422b04 <d128fc0c5c2b19224927d4fd2a46c2fe6a1f606f; version=7d1f0e167a067ed741dec08b7614d76893422b04 <e822f535273af0e8968eab7acc0cea0b90dd25af

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5Oracle LinuxCVSS: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

T1499.004Endpoint Denial of Service: Application or System Exploitation

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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