CVE-2023-53769: virt/coco/sev-guest: Double-buffer messages

Severity: critical (CVSS 9.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-08 · updated 2026-08-04

Description

In the Linux kernel, the following vulnerability has been resolved: virt/coco/sev-guest: Double-buffer messages The encryption algorithms read and write directly to shared unencrypted memory, which may leak information as well as permit the host to tamper with the message integrity. Instead, copy whole messages in or out as needed before doing any computation on them.

Affected products

Linux kernel: 5.19 — fixed in 6.4

How to fix

Upgrade to a fixed version: Linux kernel 6.4. Check the vendor advisory for mitigations.

References

https://git.kernel.org/stable/c/4b69c63f716cfda38e1210e65b68f67f6cee2ddf
https://git.kernel.org/stable/c/577a64725bfd77645986168e953d405067ee565b
https://git.kernel.org/stable/c/965006103a14703cc42043bbf9b5e0cdf7a468ad
https://git.kernel.org/stable/c/c27dafc4aa50a29ec927b3aa84ac7b430071f682

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