CVE-2025-39681

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 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. ]

Package Linux Kernel
Published 2025-09-05
Last modified 2026-05-12
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 5.8 and later are affected. Fixed in 5.10.242, 5.15.190, 6.1.149, 6.6.103, 6.12.44, 6.16.4, 6.17 and their respective stable series.

Affected from
≥ 5.8
Fixed in
✓ 5.10.242 5.10.x ✓ 5.15.190 5.15.x ✓ 6.1.149 6.1.x ✓ 6.6.103 6.6.x ✓ 6.12.44 6.12.x ✓ 6.16.4 6.16.x ✓ 6.17

References

The following references provide additional information about CVE-2025-39681 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2025-39681?

    CVE-2025-39681 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 5.8 onward and has been patched in 5.10.242, 5.15.190, 6.1.149 and others. CVE-2025-39681 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-39681?

    CVE-2025-39681 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2025-39681?

    Yes — CVE-2025-39681 has been patched. Fixed versions include 5.10.242, 5.15.190, 6.1.149 and others. If you are running Linux kernel 5.8 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-39681 actively exploited?

    No — CVE-2025-39681 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.