arm64/gcs: Fix error handling in arch_set_shadow_stack_status() (CVE-2026-45876) | HOL Guard CVE

Medium · CVSS 5.5CVE-2026-45876

arm64/gcs: Fix error handling in arch_set_shadow_stack_status()

Answer in brief

CVE-2026-45876 records a Medium severity (CVSS 5.5) vulnerability in arm64/gcs: Fix error handling in arch_set_shadow_stack_status(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published May 27, 2026Updated Jun 25, 2026Source checked Sep 19, 2026First seen by HOL Jun 25, 2026Material review Jun 25, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.5
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=b57180c75c7ebff6613886cb69ef6e283a10358b <c787a235deb33be6eda40beee8f561da5fd8cb8c \|\| >=b57180c75c7ebff6613886cb69ef6e283a10358b <a4741114c9622346c4bbb8cc2bbd88153616ffaf \|\| >=b57180c75c7ebff6613886cb69ef6e283a10358b <53c998527ffa60f9deda8974a11ad39790684159	c787a235deb33be6eda40beee8f561da5fd8cb8c, a4741114c9622346c4bbb8cc2bbd88153616ffaf, 53c998527ffa60f9deda8974a11ad39790684159
Linux/Linuxgeneric	6.13	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to c787a235deb33be6eda40beee8f561da5fd8cb8c if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
May 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Jun 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jun 25, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: arm64/gcs: Fix error handling in arch_set_shadow_stack_status() alloc_gcs() returns an error-encoded pointer on failure, which comes from do_mmap(), not NULL. The current NULL check fails to detect errors, which could lead to using an invalid GCS address. Use IS_ERR_VALUE() to properly detect errors, consistent with the check in gcs_alloc_thread_stack().

Quoted source text, attributed separately from HOL analysis.