CVE-2026-45981

Kernel service interruption via premature subchannel free

Published May 27, 2026 · Updated May 27, 2026

Use-after-free in Linux Kernel s390/cio allows local users to interrupt service when subchannel DMA-mask setup fails. The css_alloc_subchannel() error path calls kfree() after device_initialize() when DMA-mask setup fails, bypassing device reference counting and risking reuse or a second free. The path is limited to s390 channel-I/O device discovery, requires local access and a DMA-mask setup failure, and affects availability rather than stored data.

CVSS severity5.5
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux Kernel s390/cio allows local users to interrupt service when subchannel DMA-mask setup fails. The css_alloc_subchannel() error path calls kfree() after device_initialize() when DMA-mask setup fails, bypassing device reference counting and risking reuse or a second free. The path is limited to s390 channel-I/O device discovery, requires local access and a DMA-mask setup failure, and affects availability rather than stored data.

The record

CVE
CVE-2026-45981
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-401, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 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=3.10
  2. Affected versionversion=e5dcf0025d7af58f525590ac86ac27cb44714e8d <2b2ad7ad4a28ffdb9f94e6d979b88a5b12b71681
  3. Affected versionversion=e5dcf0025d7af58f525590ac86ac27cb44714e8d <6715560527e343a387e4a0d2e6c401748e89fa55
  4. Affected versionversion=e5dcf0025d7af58f525590ac86ac27cb44714e8d <abb6e07f46a740cda4f07d1b561ae4eaa7a1df42
  5. Affected versionversion=e5dcf0025d7af58f525590ac86ac27cb44714e8d <b1d4e6fb241672850296956c4d782a69363a3807
  6. Affected versionversion=e5dcf0025d7af58f525590ac86ac27cb44714e8d <c35cfbb5341ba05ad1b4476ffc3c21cc3ff8f603
  7. Affected versionversion=e5dcf0025d7af58f525590ac86ac27cb44714e8d <f65c75b0b9b5a390bc3beadcde0a6fbc3ad118f7
  8. Affected versionversion=e5dcf0025d7af58f525590ac86ac27cb44714e8d <f96c5ccf95ae5f27218c1ce2d6a3ad2d3e105424
  9. Affected versionversion=e5dcf0025d7af58f525590ac86ac27cb44714e8d <fd295a75d828c11acfcc6869c2a12cdaaf9b7722

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.10; version=e5dcf0025d7af58f525590ac86ac27cb44714e8d <2b2ad7ad4a28ffdb9f94e6d979b88a5b12b71681; version=e5dcf0025d7af58f525590ac86ac27cb44714e8d <6715560527e343a387e4a0d2e6c401748e89fa55; version=e5dcf0025d7af58f525590ac86ac27cb44714e8d <abb6e07f46a740cda4f07d1b561ae4eaa7a1df42; version=e5dcf0025d7af58f525590ac86ac27cb44714e8d <b1d4e6fb241672850296956c4d782a69363a3807; version=e5dcf0025d7af58f525590ac86ac27cb44714e8d <c35cfbb5341ba05ad1b4476ffc3c21cc3ff8f603; version=e5dcf0025d7af58f525590ac86ac27cb44714e8d <f65c75b0b9b5a390bc3beadcde0a6fbc3ad118f7; version=e5dcf0025d7af58f525590ac86ac27cb44714e8d <f96c5ccf95ae5f27218c1ce2d6a3ad2d3e105424; version=e5dcf0025d7af58f525590ac86ac27cb44714e8d <fd295a75d828c11acfcc6869c2a12cdaaf9b7722

Published CVSS scores

5.5NVDCVSS: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-401Missing Release of Memory after Effective Lifetime
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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