Linux Kernel up to 6.17.5 sctp null pointer dereference

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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.17.5. It has been rated as critical. This impacts an unknown function of the component sctp. Performing a manipulation results in null pointer dereference. This vulnerability is cataloged as CVE-2025-40240. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.17.5. This affects an unknown function of the component sctp. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: sctp: avoid NULL dereference when chunk data buffer is missing chunk->skb pointer is dereferenced in the if-block where it's supposed to be NULL only. chunk->skb can only be NULL if chunk->head_skb is not. Check for frag_list instead and do it just before replacing chunk->skb. We're sure that otherwise chunk->skb is non-NULL because of outer if() condition.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-40240 since 04/16/2025. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 277494 (Linux Distros Unpatched Vulnerability : CVE-2025-40240), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.301, 5.10.246, 5.15.196, 6.1.158, 6.6.115, 6.12.56 or 6.17.6 eliminates this vulnerability. Applying the patch 61cda2777b07d27459f5cac5a047c3edf9c8a1a9/08165c296597075763130919f2aae59b5822f016/03e80a4b04ef1fb2c61dd63216ab8d3a5dcb196f/4f6da435fb5d8a21cbf8cae5ca5a2ba0e1012b71/cb9055ba30306ede4ad920002233d0659982f1cb/7a832b0f99be19df608cb75c023f8027b1789bd1/89b465b54227c245ddc7cc9ed822231af21123ef/441f0647f7673e0e64d4910ef61a5fb8f16bfb82 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 (277494) and CERT Bund (WID-SEC-2025-2747). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Debian Linux
  • Google Cloud Platform
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux
  • Microsoft Azure Linux

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

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

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 277494
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-40240

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.4.301/5.10.246/5.15.196/6.1.158/6.6.115/6.12.56/6.17.6
Patch: 61cda2777b07d27459f5cac5a047c3edf9c8a1a9/08165c296597075763130919f2aae59b5822f016/03e80a4b04ef1fb2c61dd63216ab8d3a5dcb196f/4f6da435fb5d8a21cbf8cae5ca5a2ba0e1012b71/cb9055ba30306ede4ad920002233d0659982f1cb/7a832b0f99be19df608cb75c023f8027b1789bd1/89b465b54227c245ddc7cc9ed822231af21123ef/441f0647f7673e0e64d4910ef61a5fb8f16bfb82

Timelineinfo

04/16/2025 CVE reserved
12/04/2025 +232 days Advisory disclosed
12/04/2025 +0 days VulDB entry created
02/23/2026 +81 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-40240 (🔒)
GCVE (CVE): GCVE-0-2025-40240
GCVE (VulDB): GCVE-100-334299
CERT Bund: WID-SEC-2025-2747 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 12/04/2025 17:33
Updated: 02/23/2026 19:18
Changes: 12/04/2025 17:33 (58), 12/06/2025 20:17 (2), 01/05/2026 01:36 (7), 02/23/2026 19:18 (1)
Complete: 🔍
Cache ID: 216::103

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