CVE-2025-38000

High

In the Linux kernel, the following vulnerability has been resolved: sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue() When enqueuing the first packet to an HFSC class, hfsc_enqueue() calls the child qdisc's peek() operation before incrementing sch->q.qlen and sch->qstats.backlog. If the child qdisc uses qdisc_peek_dequeued(), this may trigger an immediate dequeue and potential packet drop. In such cases, qdisc_tree_reduce_backlog() is called, but the HFSC qdisc's qlen and backlog have not yet been updated, leading to inconsistent queue accounting. This can leave an empty HFSC class in the active list, causing further consequences like use-after-free. This patch fixes the bug by moving the increment of sch->q.qlen and sch->qstats.backlog before the call to the child qdisc's peek() operation. This ensures that queue length and backlog are always accurate when packet drops or dequeues are triggered during the peek.

Package Linux Kernel
Published 2025-06-06
Last modified 2025-12-16
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.8

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

Weakness type

CWE-416

CVE-2025-38000 is a Use After Free vulnerability

What is Use After Free?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE

Affected versions

Linux kernel versions 4.8 and later are affected. Fixed in 5.4.294, 5.10.238, 5.15.185, 6.1.141, 6.6.93, 6.12.31, 6.14.9, 6.15 and their respective stable series.

Affected from
≥ 4.8
Fixed in
✓ 5.4.294 5.4.x ✓ 5.10.238 5.10.x ✓ 5.15.185 5.15.x ✓ 6.1.141 6.1.x ✓ 6.6.93 6.6.x ✓ 6.12.31 6.12.x ✓ 6.14.9 6.14.x ✓ 6.15

References

The following references provide additional information about CVE-2025-38000 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

8 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2025-38000?

    CVE-2025-38000 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 4.8 onward and has been patched in 5.4.294, 5.10.238, 5.15.185 and others. CVE-2025-38000 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-38000?

    CVE-2025-38000 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2025-38000?

    Yes — CVE-2025-38000 has been patched. Fixed versions include 5.4.294, 5.10.238, 5.15.185 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-2025-38000 actively exploited?

    No — CVE-2025-38000 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Use After Free (CWE-416)?

    The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →

Back to
All CVEs
View on
NVD / NIST