CVE-2026-23352

Boot-time RAM loss via premature EFI cleanup

Published Mar 25, 2026 · Updated Mar 25, 2026

Memory leak in x86 EFI boot-services cleanup in Linux Kernel allows attackers to reduce available RAM during boot via unspecified vectors. efi_free_boot_services() passes memblock-reserved EFI code and data pages to memblock_free_late() before deferred memory-map initialization, so memblock_free_pages() skips uninitialized pages instead of releasing them. Exposure requires an x86 EFI boot with CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled; observed loss was about 140 MB on a 512 MB instance, reducing service capacity without reported data access or modification.

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

Memory leak in x86 EFI boot-services cleanup in Linux Kernel allows attackers to reduce available RAM during boot via unspecified vectors. efi_free_boot_services() passes memblock-reserved EFI code and data pages to memblock_free_late() before deferred memory-map initialization, so memblock_free_pages() skips uninitialized pages instead of releasing them. Exposure requires an x86 EFI boot with CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled; observed loss was about 140 MB on a 512 MB instance, reducing service capacity without reported data access or modification.

The record

CVE
CVE-2026-23352
Published
Mar 25, 2026
Updated
Mar 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-401
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 25, 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=0aed459e8487eb6ebdb4efe8cefe1eafbc704b30 <4a2cb90c538f06c873a187aa743575d48685d7a6
  2. Affected versionversion=3.0
  3. Affected versionversion=916f676f8dc016103f983c7ec54c18ecdbb6e349 <227688312fece0026fc67a00ba9a0b3611ebe95d
  4. Affected versionversion=916f676f8dc016103f983c7ec54c18ecdbb6e349 <399da820ecfe6f4f10c143e5c453d3559a04db9c
  5. Affected versionversion=916f676f8dc016103f983c7ec54c18ecdbb6e349 <6a25e25279282c5c8ade554c04c6ab9dc7902c64
  6. Affected versionversion=916f676f8dc016103f983c7ec54c18ecdbb6e349 <7dcf59422a3b0d20ddda844f856b4a1e0608a326
  7. Affected versionversion=916f676f8dc016103f983c7ec54c18ecdbb6e349 <a4b0bf6a40f3c107c67a24fbc614510ef5719980
  8. Affected versionversion=916f676f8dc016103f983c7ec54c18ecdbb6e349 <f9e9cc320854a76a39e7bc92d144554f3a727fad

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0aed459e8487eb6ebdb4efe8cefe1eafbc704b30 <4a2cb90c538f06c873a187aa743575d48685d7a6; version=3.0; version=916f676f8dc016103f983c7ec54c18ecdbb6e349 <227688312fece0026fc67a00ba9a0b3611ebe95d; version=916f676f8dc016103f983c7ec54c18ecdbb6e349 <399da820ecfe6f4f10c143e5c453d3559a04db9c; version=916f676f8dc016103f983c7ec54c18ecdbb6e349 <6a25e25279282c5c8ade554c04c6ab9dc7902c64; version=916f676f8dc016103f983c7ec54c18ecdbb6e349 <7dcf59422a3b0d20ddda844f856b4a1e0608a326; version=916f676f8dc016103f983c7ec54c18ecdbb6e349 <a4b0bf6a40f3c107c67a24fbc614510ef5719980; version=916f676f8dc016103f983c7ec54c18ecdbb6e349 <f9e9cc320854a76a39e7bc92d144554f3a727fad

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

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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

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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