What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-27 · updated 2026-06-25
• Weakness: CWE-476

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().

Affected products

• Linux kernel: from 6.13 before 6.18.14; from 6.19 before 6.19.4 — fixed in 6.18.14, 6.19.4

How to fix

Upgrade to a fixed version: Linux kernel 6.18.14, 6.19.4. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/53c998527ffa60f9deda8974a11ad39790684159
• https://git.kernel.org/stable/c/a4741114c9622346c4bbb8cc2bbd88153616ffaf
• https://git.kernel.org/stable/c/c787a235deb33be6eda40beee8f561da5fd8cb8c

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