CVE-2025-68807

Local denial of service via WBT race

Published Jan 13, 2026 · Updated Jan 13, 2026

Race condition in Linux Kernel 6.16 allows local users to hang writeback tasks through concurrent I/O submission and WBT enablement. The rwb_enabled state can change between wbt_wait throttling and wbt_track accounting, so I/O decrements an inflight counter before WBT initialization and drives it to -1. Reaching the flaw requires local I/O during the enablement race; affected writeback workers can remain stuck in wbt_wait, interrupting storage service.

CVSS severity5.5
Medium
EPSS probability0.18%
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 Linux Kernel 6.16 allows local users to hang writeback tasks through concurrent I/O submission and WBT enablement. The rwb_enabled state can change between wbt_wait throttling and wbt_track accounting, so I/O decrements an inflight counter before WBT initialization and drives it to -1. Reaching the flaw requires local I/O during the enablement race; affected writeback workers can remain stuck in wbt_wait, interrupting storage service.

The record

CVE
CVE-2025-68807
Published
Jan 13, 2026
Updated
Jan 13, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 13, 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=6.16
  2. Affected versionversion=78c271344b6f64ce24c845e54903e09928cf2061 <9869d3a6fed381f3b98404e26e1afc75d680cbf9
  3. Affected versionversion=78c271344b6f64ce24c845e54903e09928cf2061 <f55201fb3becff6a903fd29f4d1147cc7e91eb0c

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.16; version=78c271344b6f64ce24c845e54903e09928cf2061 <9869d3a6fed381f3b98404e26e1afc75d680cbf9; version=78c271344b6f64ce24c845e54903e09928cf2061 <f55201fb3becff6a903fd29f4d1147cc7e91eb0c

Published CVSS scores

5.5Amazon 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

T1499.004Application 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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