CVE-2026-45876

System crash via unchecked error-encoded GCS pointer

Published May 27, 2026 · Updated May 27, 2026

NULL pointer dereference in the arm64 GCS implementation of Linux Kernel allows local users to crash the system during shadow-stack setup. arch_set_shadow_stack_status() tests alloc_gcs() for NULL even though do_mmap() failures are returned as error-encoded pointers, then treats an invalid GCS address as usable. Exploitation requires local low-privileged access, AArch64 hardware with GCS support, and a GCS allocation failure; the published impact is limited to system availability.

CVSS severity5.5
Medium
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the arm64 GCS implementation of Linux Kernel allows local users to crash the system during shadow-stack setup. arch_set_shadow_stack_status() tests alloc_gcs() for NULL even though do_mmap() failures are returned as error-encoded pointers, then treats an invalid GCS address as usable. Exploitation requires local low-privileged access, AArch64 hardware with GCS support, and a GCS allocation failure; the published impact is limited to system availability.

The record

CVE
CVE-2026-45876
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-476, T1499
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=6.13
  2. Affected versionversion=b57180c75c7ebff6613886cb69ef6e283a10358b <53c998527ffa60f9deda8974a11ad39790684159
  3. Affected versionversion=b57180c75c7ebff6613886cb69ef6e283a10358b <a4741114c9622346c4bbb8cc2bbd88153616ffaf
  4. Affected versionversion=b57180c75c7ebff6613886cb69ef6e283a10358b <c787a235deb33be6eda40beee8f561da5fd8cb8c

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.13; version=b57180c75c7ebff6613886cb69ef6e283a10358b <53c998527ffa60f9deda8974a11ad39790684159; version=b57180c75c7ebff6613886cb69ef6e283a10358b <a4741114c9622346c4bbb8cc2bbd88153616ffaf; version=b57180c75c7ebff6613886cb69ef6e283a10358b <c787a235deb33be6eda40beee8f561da5fd8cb8c

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.8SUSECVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

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-476NULL Pointer Dereference
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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