Ubuntu 25.10 AMD Microcode Critical Data Exposure Vulnerability USN-8475

Several security issues were fixed in AMD Microcode. Software Description: - amd64-microcode: Platform firmware and microcode for AMD CPUs and SoCs Details: Oleksii Oleksenko, Cedric Fournet, Jana Hofmann, Boris Köpf, Stavros Volos, and Flavien Solt discovered that some AMD processors may allow an attacker to infer data from stores, potentially resulting in the leakage of privileged information. A local attacker could possibly use this to expose sensitive information. (CVE-2024-36350, CVE-2024-36357) It was discovered that some AMD Zen 5 processors supporting RDSEED instruction did not properly handle entropy, potentially resulting in the consumption of insufficiently random values. A local attacker could possibly use this issue to influence the values returned by the RDSEED instruction causing loss of confidentiality and integrity. (CVE-2025-62626)

Several security issues were fixed in AMD Microcode.

Software Description:

- amd64-microcode: Platform firmware and microcode for AMD CPUs and SoCs

Oleksii Oleksenko, Cedric Fournet, Jana Hofmann, Boris Köpf, Stavros Volos,

and Flavien Solt discovered that some AMD processors may allow an attacker

to infer data from stores, potentially resulting in the leakage of

privileged information. A local attacker could possibly use this to expose

sensitive information. (CVE-2024-36350, CVE-2024-36357)

It was discovered that some AMD Zen 5 processors supporting RDSEED

instruction did not properly handle entropy, potentially resulting in the

consumption of insufficiently random values. A local attacker could

possibly use this issue to influence the values returned by the RDSEED

instruction causing loss of confidentiality and integrity. (CVE-2025-62626)

The problem can be corrected by updating your system to the following package versions: Ubuntu 25.10 amd64-microcode 3.20251202.1ubuntu0.25.10.1 Ubuntu 24.04 LTS amd64-microcode 3.20251202.1ubuntu0.24.04.1 After a standard system update you need to reboot your computer to make all the necessary changes. ATTENTION: For the most comprehensive protection, users should update their system BIOS/UEFI to the latest version provided by their hardware vendor. If the BIOS has not been updated, this microcode update will apply the latest available mitigations that can be delivered via the operating system. For more information, please see:

CVE-2024-36350, CVE-2024-36357, CVE-2025-62626

Ubuntu Security Notice USN-8475-1

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