USN-7866-1: Intel Microcode vulnerabilities

USN-7866-1: Intel Microcode vulnerabilities

Publication date: 10 November 2025
Overview: Several security issues were fixed in Intel Microcode.

Packages
intel-microcode - Processor microcode for Intel CPUs

Details
Barak Gross discovered that some Intel® Xeon® processors with SGX enabled
did not properly handle buffer restrictions. A local authenticated user
could potentially use this issue to escalate their privileges.
(CVE-2025-20053)

Avinash Maddy discovered that some Intel® processors did not properly
isolate or compartmentalize the stream cache mechanisms. A local
authenticated user could potentially use this issue to escalate their
privileges. (CVE-2025-20109)

Joseph Nuzman discovered that some Intel® Xeon® processors did not properly
manage references to active allocate resources. A local authenticated user
could potentially use this issue to cause a denial of service (system
crash). (CVE-2025-21090)

It was discovered that some Intel® Xeon® 6 processors did not properly
provide sufficient granularity of access control in the out of band
management service module (OOB-MSM). An authenticated user could
potentially use this issue to escalate their privileges. (CVE-2025-22839)

It was discovered that some Intel® Xeon® 6 Scalable processors did not
properly handle a specific sequence of processor instructions, leading to
unexpected behavior. A local authenticated user could potentially use this
issue to escalate their privileges. (CVE-2025-22840)

Joseph Nuzman discovered that some Intel® Xeon® 6 processors with Intel®
Trust Domain Extensions (Intel® TDX) did not properly handle overlap
between protected memory ranges. A local authenticated user could
potentially use this issue to escalate their privileges. (CVE-2025-22889)

Avraham Shalev discovered that some Intel® Xeon® processors did not
properly provide sufficient control flow management in the Alias Checking
Trusted Module (ACTM) firmware. A local authenticated user could
potentially use this issue to escalate their privileges. (CVE-2025-24305)

Aviv Eisen and Avraham Shalev discovered that some Intel® Xeon® 6
processors when using Intel® SGX or Intel® TDX did not properly protect
against out-of-bounds writes in the memory subsystem. A local authenticated
user could potentially use this issue to escalate their privileges.
(CVE-2025-26403)

Aviv Eisen and Avraham Shalev discovered that some Intel® Xeon® 6
processors when using Intel® SGX or Intel® TDX did not properly implement
security checks in the DDRIO configuration. A local authenticated user
could potentially use this issue to escalate their privileges.
(CVE-2025-32086)

Update instructions
The problem can be corrected by updating your system to the following package versions:

• 25.10 questing intel-microcode – 3.20250812.0ubuntu0.25.10.1
• 25.04 plucky intel-microcode – 3.20250812.0ubuntu0.25.04.1
• 24.04 LTS noble intel-microcode – 3.20250812.0ubuntu0.24.04.1
• 22.04 LTS jammy intel-microcode – 3.20250812.0ubuntu0.22.04.1
• 20.04 LTS focal intel-microcode – 3.20250812.0ubuntu0.20.04.1+esm1
• 18.04 LTS bionic intel-microcode – 3.20250812.0ubuntu0.18.04.1+esm1
• 16.04 LTS xenial intel-microcode – 3.20250812.0ubuntu0.16.04.1+esm1