CVE-2024-36909
A flaw in the Linux kernel's VMBus driver allows a malicious host to cause memory intended to be encrypted to remain shared and unencrypted. This occurs when certain memory encryption functions fail during the handling of ring buffers.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Users running Linux kernel version 6.9 or affected versions in CoCo (Confidential Computing) Virtual Machines.
Real-world impact
An untrusted host could access sensitive data by forcing the system to use unencrypted, shared memory instead of the intended encrypted memory.
Why this severity
The critical score reflects that an attacker can achieve a total loss of confidentiality, integrity, and availability by exploiting the way memory is handled in CoCo VMs.
What to do about it
- 01Upgrade the Linux kernel to a version that includes the fix for the hv: vmbus driver.
NVD-referenced vendor advisory
Timeline
- May 30, 2024 · May 30, 2024PublishedDisclosed and added to the National Vulnerability Database.
- Aug 4, 2026 · 2d agoAdvisory updatedThe NVD record was last revised.
- Aug 5, 2026 · 1d agoOfficial fix availableA vendor patch or mitigation now exists — see the remediation steps above.