Bug 2476925 (CVE-2025-61971)

Summary: CVE-2025-61971 microcode_ctl: Microcode: Loss of SEV-SNP guest integrity via NBIO register modification
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the microcode that manages NBIO registers. A local attacker with administrative privileges could exploit a missing security control, allowing them to alter critical system configurations. This could compromise the integrity of virtual machines protected by Secure Encrypted Virtualization-Secure Nested Paging (SEV-SNP), potentially leading to unauthorized data tampering or execution within the guest.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2526216, 2489142    
Bug Blocks:    

Description OSIDB Bzimport 2026-05-13 04:01:29 UTC 
Missing lock bit protection for NBIO registers could allow a local admin-privileged attacker to modify MMIO routing configurations, potentially resulting in loss of SEV-SNP guest integrity.