CVE-2025-39673

Medium

In the Linux kernel, the following vulnerability has been resolved: ppp: fix race conditions in ppp_fill_forward_path ppp_fill_forward_path() has two race conditions: 1. The ppp->channels list can change between list_empty() and list_first_entry(), as ppp_lock() is not held. If the only channel is deleted in ppp_disconnect_channel(), list_first_entry() may access an empty head or a freed entry, and trigger a panic. 2. pch->chan can be NULL. When ppp_unregister_channel() is called, pch->chan is set to NULL before pch is removed from ppp->channels. Fix these by using a lockless RCU approach: - Use list_first_or_null_rcu() to safely test and access the first list entry. - Convert list modifications on ppp->channels to their RCU variants and add synchronize_net() after removal. - Check for a NULL pch->chan before dereferencing it.

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

CVSS 3.1 score

4.7

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

Weakness type

CWE-362

CVE-2025-39673 is a Race Condition vulnerability

What is Race Condition?

The product contains a code sequence that can run concurrently with other code, creating unexpected states. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.13 and later are affected. Fixed in 5.15.190, 6.1.149, 6.6.103, 6.12.44, 6.16.4, 6.17 and their respective stable series.

Affected from
≥ 5.13
Fixed in
✓ 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-2025-39673 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

6 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2025-39673?

    CVE-2025-39673 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10 , classified as a Race Condition flaw (CWE-362) . It affects Linux kernel versions from 5.13 onward and has been patched in 5.15.190, 6.1.149, 6.6.103 and others. CVE-2025-39673 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-39673?

    CVE-2025-39673 has a CVSS score of 4.7 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2025-39673?

    Yes — CVE-2025-39673 has been patched. Fixed versions include 5.15.190, 6.1.149, 6.6.103 and others. If you are running Linux kernel 5.13 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-39673 actively exploited?

    No — CVE-2025-39673 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Race Condition (CWE-362)?

    The product contains a code sequence that can run concurrently with other code, creating unexpected states. View CWE-362 on MITRE CWE →

Back to
All CVEs
View on
NVD / NIST