Is CVE-2021-22566 actively exploited?

No active exploitation of CVE-2021-22566 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-22566 be exploited remotely?

Yes. CVE-2021-22566 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-22566?

CVE-2021-22566 has a CVSS score of 9.8 (CRITICAL).

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CRITICAL

CVE-2021-22566

CWE-275Published: January 18, 2022· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

An incorrect setting of UXN bits within mmu_flags_to_s1_pte_attr lead to privileged executable pages being mapped as executable from an unprivileged context. This can be leveraged by an attacker to bypass executability restrictions of kernel-mode pages from user-mode. An incorrect setting of PXN bits within mmu_flags_to_s1_pte_attr lead to unprivileged executable pages being mapped as executable from a privileged context. This can be leveraged by an attacker to bypass executability restrictions of user-mode pages from kernel-mode. Typically this allows a potential attacker to circumvent a mitigation, making exploitation of potential kernel-mode vulnerabilities easier. We recommend updating kernel beyond commit 7d731b4e9599088ac3073956933559da7bca6a00 and rebuilding.

NVD Source

Technical Analysis

CVE-2021-22566 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.