CVE-2026-31654

Local service interruption via unreleased shmem file

Published Apr 24, 2026 · Updated Apr 24, 2026

Memory leak in Linux Kernel 6.19 through 6.19.12 allows local users to interrupt service by mapping /dev/zero with MAP_SHARED. The __mmap_region error path fails to call fput() on the replacement shmem file created by mmap_zero_prepare when __mmap_new_vma fails. Triggering the leak requires a local mapping request and a subsequent allocation failure; repeated successful triggering consumes unreleased kernel memory and can interrupt service.

CVSS severity5.5
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in Linux Kernel 6.19 through 6.19.12 allows local users to interrupt service by mapping /dev/zero with MAP_SHARED. The __mmap_region error path fails to call fput() on the replacement shmem file created by mmap_zero_prepare when __mmap_new_vma fails. Triggering the leak requires a local mapping request and a subsequent allocation failure; repeated successful triggering consumes unreleased kernel memory and can interrupt service.

The record

CVE
CVE-2026-31654
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-401, T1499
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=605f6586ecf78395f0185ab24c368fb46a06e434 <61fc8eaf2ab214b32c7bce52597c80cf0ca41ada
  2. Affected versionversion=605f6586ecf78395f0185ab24c368fb46a06e434 <894f99eb535edc4514f756818f3c4f688ba53a59
  3. Affected versionversion=6.19

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=605f6586ecf78395f0185ab24c368fb46a06e434 <61fc8eaf2ab214b32c7bce52597c80cf0ca41ada; version=605f6586ecf78395f0185ab24c368fb46a06e434 <894f99eb535edc4514f756818f3c4f688ba53a59; version=6.19

Published CVSS scores

5.5NIST NVDCVSS: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

CWE-401Missing Release of Memory after Effective Lifetime
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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