CVE-2025-39742

Medium

In the Linux kernel, the following vulnerability has been resolved: RDMA: hfi1: fix possible divide-by-zero in find_hw_thread_mask() The function divides number of online CPUs by num_core_siblings, and later checks the divider by zero. This implies a possibility to get and divide-by-zero runtime error. Fix it by moving the check prior to division. This also helps to save one indentation level.

Package Linux Kernel
Published 2025-09-11
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

Weakness type

CWE-369

CVE-2025-39742 is a Divide By Zero vulnerability

What is Divide By Zero?

The product divides a value by zero, causing a crash or unexpected behaviour. Learn more on MITRE CWE

Affected versions

Linux kernel versions 4.8 and later are affected. Fixed in 5.4.297, 5.10.241, 5.15.190, 6.1.149, 6.6.103, 6.12.43, 6.15.11, 6.16.2, 6.17 and their respective stable series.

Affected from
≥ 4.8
Fixed in
✓ 5.4.297 5.4.x ✓ 5.10.241 5.10.x ✓ 5.15.190 5.15.x ✓ 6.1.149 6.1.x ✓ 6.6.103 6.6.x ✓ 6.12.43 6.12.x ✓ 6.15.11 6.15.x ✓ 6.16.2 6.16.x ✓ 6.17

References

The following references provide additional information about CVE-2025-39742 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-2025-39742?

    CVE-2025-39742 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Divide By Zero flaw (CWE-369) . It affects Linux kernel versions from 4.8 onward and has been patched in 5.4.297, 5.10.241, 5.15.190 and others. CVE-2025-39742 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-39742?

    CVE-2025-39742 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-2025-39742?

    Yes — CVE-2025-39742 has been patched. Fixed versions include 5.4.297, 5.10.241, 5.15.190 and others. If you are running Linux kernel 4.8 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-39742 actively exploited?

    No — CVE-2025-39742 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Divide By Zero (CWE-369)?

    The product divides a value by zero, causing a crash or unexpected behaviour. View CWE-369 on MITRE CWE →