SB20260827126 - Use-after-free in Linux kernel net driver

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Main Vulnerability Database SB20260827126

SB20260827126 - Use-after-free in Linux kernel net driver

Published: August 27, 2026

Security Bulletin ID SB20260827126
CSH Severity
High
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-74743)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a use-after-free in the macvlan network device handling in drivers/net/macvlan.c when processing packets on a macvlan device backed by a lower device that requires additional headroom or tailroom. A remote attacker can send network traffic that triggers insufficient buffer space handling to execute arbitrary code.

The issue can be triggered when the lower device requires extra header or trailer space, such as with macsec, ipsec, wireguard, tunnels, or veth with rx headroom.


Remediation

Install update from vendor's website.

References