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

What is CVE-2026-45876?

CVE-2026-45876 is a medium-severity vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official 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().

Weakness: CWE-476

Which versions are affected by CVE-2026-45876?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-45876?

Apply the vendor's patch.

Is CVE-2026-45876 being exploited?

There is no known exploitation of CVE-2026-45876 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2026-45876, DEBIAN-CVE-2026-45876, GHSA-c8fp-ff95-66mv, UBUNTU-CVE-2026-45876.