CVE-2025-39847

Medium

In the Linux kernel, the following vulnerability has been resolved: ppp: fix memory leak in pad_compress_skb If alloc_skb() fails in pad_compress_skb(), it returns NULL without releasing the old skb. The caller does: skb = pad_compress_skb(ppp, skb); if (!skb) goto drop; drop: kfree_skb(skb); When pad_compress_skb() returns NULL, the reference to the old skb is lost and kfree_skb(skb) ends up doing nothing, leading to a memory leak. Align pad_compress_skb() semantics with realloc(): only free the old skb if allocation and compression succeed. At the call site, use the new_skb variable so the original skb is not lost when pad_compress_skb() fails.

Package Linux Kernel
Published 2025-09-19
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-401

CVE-2025-39847 is a Memory Leak vulnerability

What is Memory Leak?

The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE

Affected versions

Linux kernel versions 2.6.15 and later are affected. Fixed in 5.4.299, 5.10.243, 5.15.192, 6.1.151, 6.6.105, 6.12.46, 6.16.6, 6.17 and their respective stable series.

Affected from
≥ 2.6.15
Fixed in
✓ 5.4.299 5.4.x ✓ 5.10.243 5.10.x ✓ 5.15.192 5.15.x ✓ 6.1.151 6.1.x ✓ 6.6.105 6.6.x ✓ 6.12.46 6.12.x ✓ 6.16.6 6.16.x ✓ 6.17

References

The following references provide additional information about CVE-2025-39847 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-2025-39847?

    CVE-2025-39847 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 2.6.15 onward and has been patched in 5.4.299, 5.10.243, 5.15.192 and others. CVE-2025-39847 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-39847?

    CVE-2025-39847 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-2025-39847?

    Yes — CVE-2025-39847 has been patched. Fixed versions include 5.4.299, 5.10.243, 5.15.192 and others. If you are running Linux kernel 2.6.15 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-39847 actively exploited?

    No — CVE-2025-39847 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Memory Leak (CWE-401)?

    The product does not release memory after use, causing gradual resource exhaustion. View CWE-401 on MITRE CWE →

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