Linux Kernel up to 6.17.2 ipv6 ip6_xmit use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.6$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.17.2. It has been classified as critical. Impacted is the function ip6_xmit of the component ipv6. The manipulation leads to use after free. This vulnerability is listed as CVE-2025-40135. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.17.2. This issue affects the function ip6_xmit of the component ipv6. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ipv6: use RCU in ip6_xmit() Use RCU in ip6_xmit() in order to use dst_dev_rcu() to prevent possible UAF.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2025-40135 since 04/16/2025. The exploitation is known to be easy. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 02/08/2026).

The vulnerability scanner Nessus provides a plugin with the ID 279677 (openSUSE 16 Security Update : kernel (openSUSE-SU-2025:20172-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.17.3 or 6.18-rc1 eliminates this vulnerability. Applying the patch f7f9e924f23684b4b23cd9f976cceab24a968e34/9085e56501d93af9f2d7bd16f7fcfacdde47b99c 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 (279677) and CERT Bund (WID-SEC-2025-2579). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
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: 279677
Nessus Name: openSUSE 16 Security Update : kernel (openSUSE-SU-2025:20172-1)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.17.3/6.18-rc1
Patch: f7f9e924f23684b4b23cd9f976cceab24a968e34/9085e56501d93af9f2d7bd16f7fcfacdde47b99c

Timelineinfo

04/16/2025 CVE reserved
11/12/2025 +210 days Advisory disclosed
11/12/2025 +0 days VulDB entry created
02/08/2026 +88 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-40135 (🔒)
GCVE (CVE): GCVE-0-2025-40135
GCVE (VulDB): GCVE-100-332183
CERT Bund: WID-SEC-2025-2579 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 11/12/2025 13:38
Updated: 02/08/2026 03:50
Changes: 11/12/2025 13:38 (59), 12/18/2025 08:34 (7), 12/25/2025 05:32 (2), 12/30/2025 17:38 (1), 02/08/2026 03:50 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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