Linux Kernel up to 6.17-rc5 xcan_write_frame use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.7$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.1.152/6.6.106/6.12.47/6.16.7/6.17-rc5. It has been rated as critical. Affected is the function xcan_write_frame. The manipulation leads to use after free. This vulnerability is uniquely identified as CVE-2025-39873. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.1.152/6.6.106/6.12.47/6.16.7/6.17-rc5. This issue affects the function xcan_write_frame. 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: can: xilinx_can: xcan_write_frame(): fix use-after-free of transmitted SKB can_put_echo_skb() takes ownership of the SKB and it may be freed during or after the call. However, xilinx_can xcan_write_frame() keeps using SKB after the call. Fix that by only calling can_put_echo_skb() after the code is done touching the SKB. The tx_lock is held for the entire xcan_write_frame() execution and also on the can_get_echo_skb() side so the order of operations does not matter. An earlier fix commit 3d3c817c3a40 ("can: xilinx_can: Fix usage of skb memory") did not move the can_put_echo_skb() call far enough. [mkl: add "commit" in front of sha1 in patch description] [mkl: fix indention]

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2025-39873 since 04/16/2025. The exploitation is known to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 02/16/2026).

The vulnerability scanner Nessus provides a plugin with the ID 265871 (Linux Distros Unpatched Vulnerability : CVE-2025-39873), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.153, 6.6.107, 6.12.48, 6.16.8 or 6.17-rc6 eliminates this vulnerability. Applying the patch 1139321161a3ba5e45e61e0738b37f42f20bc57a/94b050726288a56a6b8ff55aa641f2fedbd3b44c/725b33deebd6e4c96fe7893f384510a54258f28f/668cc1e3bb21101d074e430de1b7ba8fd10189e7/ef79f00be72bd81d2e1e6f060d83cf7e425deee4 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 (265871) and CERT Bund (WID-SEC-2025-2107). Several companies clearly confirm that VulDB is the primary source for best 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
  • Dell Secure Connect Gateway
  • IBM QRadar SIEM
  • Dell NetWorker

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.7

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

NVD Base Score: 7.8
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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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: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 265871
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-39873

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.153/6.6.107/6.12.48/6.16.8/6.17-rc6
Patch: 1139321161a3ba5e45e61e0738b37f42f20bc57a/94b050726288a56a6b8ff55aa641f2fedbd3b44c/725b33deebd6e4c96fe7893f384510a54258f28f/668cc1e3bb21101d074e430de1b7ba8fd10189e7/ef79f00be72bd81d2e1e6f060d83cf7e425deee4

Timelineinfo

04/16/2025 CVE reserved
09/23/2025 +160 days Advisory disclosed
09/23/2025 +0 days VulDB entry created
02/16/2026 +146 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-39873 (🔒)
GCVE (CVE): GCVE-0-2025-39873
GCVE (VulDB): GCVE-100-325577
CERT Bund: WID-SEC-2025-2107 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 09/23/2025 08:27
Updated: 02/16/2026 07:56
Changes: 09/23/2025 08:27 (58), 09/28/2025 20:29 (2), 12/01/2025 19:25 (7), 01/12/2026 04:53 (1), 01/21/2026 01:40 (11), 02/09/2026 08:13 (1), 02/16/2026 07:56 (1)
Complete: 🔍
Cache ID: 216::103

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

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