VDB-325033 · CVE-2025-39847 · Nessus 265465

Linux Kernel up to 6.17-rc4 alloc_skb new_skb memory leak

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5.5	$0-$5k	0.00

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 6.17-rc4. Impacted is the function alloc_skb. This manipulation of the argument new_skb causes memory leak. This vulnerability appears as CVE-2025-39847. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.17-rc4. It has been declared as critical. Affected by this vulnerability is the function alloc_skb. The manipulation of the argument new_skb with an unknown input leads to a memory leak vulnerability. The CWE definition for the vulnerability is CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. As an impact it is known to affect availability. The summary by CVE is:

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.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2025-39847 since 04/16/2025. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 265465 (Linux Distros Unpatched Vulnerability : CVE-2025-39847), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.299, 5.10.243, 5.15.192, 6.1.151, 6.6.105, 6.12.46, 6.16.6 or 6.17-rc5 eliminates this vulnerability. Applying the patch 9ca6a040f76c0b149293e430dabab446f3fc8ab7/87a35a36742df328d0badf4fbc2e56061c15846c/0b21e9cd4559102da798bdcba453b64ecd7be7ee/1d8b354eafb8876d8bdb1bef69c7d2438aacfbe8/85c1c86a67e09143aa464e9bf09c397816772348/631fc8ab5beb9e0ec8651fb9875b9a968e7b4ae4/33a5bac5f14772730d2caf632ae97b6c2ee95044/4844123fe0b853a4982c02666cb3fd863d701d50 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (265465) and CERT Bund (WID-SEC-2025-2099). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

Debian Linux
Amazon Linux 2
Red Hat Enterprise Linux
Ubuntu Linux
SUSE Linux
Oracle Linux
IBM QRadar SIEM
SUSE openSUSE
RESF Rocky Linux
Open Source Linux Kernel
Dell Secure Connect Gateway
Dell NetWorker
Dell ECS

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

License

open-source

Website

Vendor: https://www.kernel.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory leak
CWE: CWE-401 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 265465
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-39847

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Timelineinfo

04/16/2025 CVE reserved
09/19/2025 +156 days Advisory disclosed
09/19/2025 +0 days VulDB entry created
06/24/2026 +278 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-39847 (🔒)
GCVE (CVE): GCVE-0-2025-39847
GCVE (VulDB): GCVE-100-325033
CERT Bund: WID-SEC-2025-2099 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 09/19/2025 18:10
Updated: 06/24/2026 10:28
Changes: 09/19/2025 18:10 (59), 09/23/2025 03:19 (2), 10/20/2025 20:11 (7), 11/03/2025 12:45 (1), 11/12/2025 04:15 (1), 11/29/2025 07:12 (1), 12/22/2025 10:25 (1), 01/20/2026 17:56 (10), 06/24/2026 10:28 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.