CVE-2025-71070

Completed-request access via leaked ublk reference

Published Jan 13, 2026 · Updated Jan 13, 2026

Reference-count cleanup errors in the Linux kernel ublk driver allow local users to access completed requests after a ublk server exits. The UBLK_REFCOUNT_INIT value survives because __ublk_fail_req() completes outstanding I/O without decrementing or resetting the request reference. A local ublk server process must close its character device with requests pending; user-copy or zero-copy operations can then target requests already marked complete and trigger kernel warnings.

CVSS severityUnavailable
Unscored
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reference-count cleanup errors in the Linux kernel ublk driver allow local users to access completed requests after a ublk server exits. The UBLK_REFCOUNT_INIT value survives because __ublk_fail_req() completes outstanding I/O without decrementing or resetting the request reference. A local ublk server process must close its character device with requests pending; user-copy or zero-copy operations can then target requests already marked complete and trigger kernel warnings.

The record

CVE
CVE-2025-71070
Published
Jan 13, 2026
Updated
Jan 13, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
Unavailable
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=6.15
  2. Affected versionversion=e537193fc4a43b48ac51cc6366319e15e32dd540
  3. Affected versionversion=e63d2228ef831af36f963b3ab8604160cfff84c1 <13456b4f1033d911f8bf3a0a1195656f293ba0f6
  4. Affected versionversion=e63d2228ef831af36f963b3ab8604160cfff84c1 <daa24603d9f0808929514ee62ced30052ca7221c

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.15; version=e537193fc4a43b48ac51cc6366319e15e32dd540; version=e63d2228ef831af36f963b3ab8604160cfff84c1 <13456b4f1033d911f8bf3a0a1195656f293ba0f6; version=e63d2228ef831af36f963b3ab8604160cfff84c1 <daa24603d9f0808929514ee62ced30052ca7221c

Published CVSS scores

No CVSS assessment is available in this record.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

No sourced classifications are available.

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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