Go to homepageCyberStrike

Menu

Star on GitHub · 3.2k
Sign inDownload

CVE-2025-39681

5.5 · MEDIUM

In the Linux kernel, the following vulnerability has been resolved: x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper Since 923f3a2b48bd ("x86/resctrl: Query LLC monitoring pr…

Published Sep 5, 2025EPSS 0.18%

Overview

CVE-2025-39681 is a medium-severity vulnerability. It was published on September 5, 2025 and has a CVSS 3.1 base score of 5.5 (MEDIUM).

This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.

Technical description

In the Linux kernel, the following vulnerability has been resolved:

x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper

Since

923f3a2b48bd ("x86/resctrl: Query LLC monitoring properties once during boot")

resctrl_cpu_detect() has been moved from common CPU initialization code to

the vendor-specific BSP init helper, while Hygon didn't put that call in their

code.

This triggers a division by zero fault during early booting stage on our

machines with X86_FEATURE_CQM* supported, where get_rdt_mon_resources() tries

to calculate mon_l3_config with uninitialized boot_cpu_data.x86_cache_occ_scale.

Add the missing resctrl_cpu_detect() in the Hygon BSP init helper.

[ bp: Massage commit message. ]

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

Refgit.kernel.org/stable/c/62f12cde10118253348a7540e85606869bd69432Refgit.kernel.org/stable/c/7207923d8453ebfb35667c1736169f2dd796772eRefgit.kernel.org/stable/c/873f32201df8876bdb2563e3187e79149427cab4Refgit.kernel.org/stable/c/a9e5924daa954c9f585c1ca00358afe71d6781c4Refgit.kernel.org/stable/c/d23264c257a70dbe021b43b3bc2ee16134cd2c69Refgit.kernel.org/stable/c/d8df126349dad855cdfedd6bbf315bad2e901c2fRefgit.kernel.org/stable/c/fb81222c1559f89bfe3aa1010f6d112531d55353Reflists.debian.org/debian-lts-announce/2025/10/msg00007.htmlReflists.debian.org/debian-lts-announce/2025/10/msg00008.htmlRefcert-portal.siemens.com/productcert/html/ssa-019113.html

How CyberStrike helps

Frequently asked questions

What is CVE-2025-39681?

CVE-2025-39681 is a medium-severity vulnerability. It was published on September 5, 2025 and has a CVSS 3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2025-39681?

This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.

How do I fix or remediate CVE-2025-39681?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2025-39681?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2025-39681 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related MEDIUM CVEs from 2025

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999