ALAS2-2026-3872

References: CVE-2025-31936  CVE-2025-31938  CVE-2025-35973  CVE-2026-20707  CVE-2026-20713  CVE-2026-20716  CVE-2026-20901  CVE-2026-20917 
FAQs regarding Amazon Linux ALAS/CVE Severity

Issue Overview:

Improper handling of overlap between protected memory ranges for some Intel(R) Xeon(R) 6 processors when using Intel(R) TDX within SMM may allow an escalation of privilege. SMM adversary with a privileged user combined with a high complexity attack may enable escalation of privilege. This result may potentially occur via local access when attack requirements are present with special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (high), integrity (high) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (none), integrity (none) and availability (none) impacts. (CVE-2025-31936)

Insufficient granularity of access control in some subsystem for some Intel(R) Xeon(R) 6 Scalable processors with Intel(R) TDX may allow an information disclosure. Authorized adversary with an authenticated user combined with a high complexity attack may enable data exposure. This result may potentially occur via local access when attack requirements are present with special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (none), integrity (none) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (high), integrity (none) and availability (none) impacts. (CVE-2025-31938)

Improper handling of values for some Intel(R) Processors within Ring 0: Kernel, Hypervisor and Bare Metal OS may allow an escalation of privilege. Authorized adversary with a privileged user combined with a high complexity attack may enable escalation of privilege. This result may potentially occur via local access when attack requirements are present with special internal knowledge and require no user interaction. The potential vulnerability may impact the confidentiality (low), integrity (low) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (high), integrity (high) and availability (none) impacts. (CVE-2025-35973)

Hardware logic contains race conditions for some 3rd Gen Intel(R) Xeon(R) Scalable Processors within Ring 3: unprivileged software may allow a denial of service. Unprivileged software adversary with an authenticated user combined with a high complexity attack may enable denial of service. This result may potentially occur via local access when attack requirements are not present with special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (none), integrity (none) and availability (high) of the vulnerable system, resulting in subsequent system confidentiality (none), integrity (none) and availability (high) impacts. (CVE-2026-20707)

Always-incorrect control flow implementation in some firmware for some Intel(R) Xeon(R) processors may allow an escalation of privilege. System software adversary with a privileged user combined with a high complexity attack may enable escalation of privilege. This result may potentially occur via local access when attack requirements are not present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (none), integrity (none) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (high), integrity (high) and availability (none) impacts. (CVE-2026-20713)

Improper access control for some Intel(R) Processors within Ring 3: User Applications may allow an escalation of privilege. Simple hardware adversary with an authenticated user combined with a high complexity attack may enable escalation of privilege. This result may potentially occur via local access when attack requirements are present with special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (high), integrity (high) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (none), integrity (none) and availability (none) impacts. (CVE-2026-20716)

Improper input validation for some Intel(R) Xeon(R) processors within firmware may allow an escalation of privilege. Startup code and smm adversary with a privileged user combined with a high complexity attack may enable data alteration. This result may potentially occur via local access when attack requirements are present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (none), integrity (none) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (none), integrity (high) and availability (none) impacts. (CVE-2026-20901)

Exposure of sensitive information caused by incorrect data forwarding during transient execution for some Intel(R) Processors within Ring 0: Hypervisor and Kernel may allow information disclosure. System software adversary with a privileged user combined with a high complexity attack may enable data exposure. This result may potentially occur via local access when attack requirements are not present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (none), integrity (none) and availability (none) of the vulnerable system, resulting in subsequent system confidentiality (high), integrity (none) and availability (none) impacts. (CVE-2026-20917)

Issue Correction:
Run yum update microcode_ctl or yum update --advisory ALAS2-2026-3872 to update your system.
System reboot is required in order to complete this update.

New Packages:

i686:
    microcode_ctl-2.1-47.amzn2.4.28.i686
    microcode_ctl-debuginfo-2.1-47.amzn2.4.28.i686

src:
    microcode_ctl-2.1-47.amzn2.4.28.src

x86_64:
    microcode_ctl-2.1-47.amzn2.4.28.x86_64
    microcode_ctl-debuginfo-2.1-47.amzn2.4.28.x86_64