SB20260625244 - Use-after-free in Linux kernel core



SB20260625244 - Use-after-free in Linux kernel core

Published: June 25, 2026

Security Bulletin ID SB20260625244
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Code execution

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-52943)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local user to escalate privileges.

The vulnerability exists due to a use-after-free in pskb_carve_inside_header() and pskb_carve_inside_nonlinear() when copying skb_shared_info for MSG_ZEROCOPY skbs. A local user can trigger repeated zerocopy skb operations to escalate privileges.

The issue is caused by copying the destructor_arg pointer into a new skb_shared_info without incrementing the associated zerocopy reference count, which can prematurely free ubuf_info_msgzc while transmit skbs still hold live references.


Remediation

Install update from vendor's website.