Vulnerability Database

352,427

Total vulnerabilities in the database

CVE-2025-39873 — linux / linux_kernel

Use After Free

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]

  • Published: Sep 23, 2025
  • Updated: Jan 21, 2026
  • CVE: CVE-2025-39873
  • Severity: High
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: High
  • Score: 7.8
  • AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWEs:

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

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Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

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